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Untitled Document

[TO BE PUBLISHED IN THE GAZETTE OF INDIA, EXTRA ORDINARY, PART II SECTION 3 SUB-SECTION (i)]

GOVERNMENT OF INDIA

MINISTRY OF CONSUMER AFFAIRS, FOOD AND PUBLIC DISTRIBUTION

(DEPARTMENT OF CONSUMER AFFAIRS)

NOTIFICATION

New Delhi, the ...........2011

 

GSR……….In exercise of the powers conferred by sub-section (1) read with clauses (c),(f),(h), (i) and (s) of sub-section (2) of section 52 of The Legal Metrology Act 2009, (1 of 2010), the Central Government hereby makes the following rules, namely

CHAPTER I
PRELIMINARY

1. Short title and commencement

(1)  These rules may be called the Legal Metrology (General) Rules, 2011.

(2) They shall come into force on the 1 st d ay of March , 2011.

2. Definitions

In these rules, unless the context otherwise requires,—

(a) “Act” means the Legal Metrology Act, 2009 (1 of 2010);

(b) “Schedule” means a Schedule appended to these rules;

(c) “Section” means a Section of the Act;

(d) words and expressions used in these rules and not defined but defined in the Act shall have the meanings respectively assigned to them in the Act.

CHAPTER II
SPECIFICATIONS OF STANDARDS OF WEIGHTS AND MEASURES

3. Reference standards

(1) Every reference standard weight shall conform, as regards denomination, material used in construction, and design, to the specifications laid down in Part I of First Schedule.

(2) The maximum permissible error in respect of any reference standard weight, on verification or re-verification after adjustment, shall be such as is specified in Part I of First Schedule.

(3) Every reference standard metre bar shall conform, as regards material used in construction, and design, to the specifications laid down in Part II of First Schedule.

(4) The maximum permissible error in respect of any reference standard metre bar, on verification or re-verification, shall be such as is specified in Part II of First Schedule.

4. Secondary standards

(1) Every secondary standard weight shall conform, as regards denomination, material used in construction, and design, to the specifications laid down in Part I of Second Schedule.

(2) The maximum permissible error in respect of any secondary standard weight, on verification or re-verification after adjustment, shall be such as is specified in Part I of Second Schedule.

(3) Every secondary standard metre bar shall conform, as regards material used in construction, and design, to the specifications laid down in Part II of Second Schedule.

(4) The maximum permissible error in respect of any secondary standard metre bar, on verification or re-verification, shall be such as is specified in Part II of Second Schedule.

(5) Every secondary standard capacity measure shall conform, as regards denomination, material used in construction, and design, to the specifications laid down in Part III of Second Schedule.

(6) The maximum permissible error in respect of any secondary standard capacity measure, on verification or re-verification after adjustment, shall be such as is specified in Part III of Second Schedule.

5. Working standards

(1) Every working standard weight shall conform, as regards denomination, material used in construction, and design, to the specifications laid down in Part I of Third Schedule.

(2) The maximum permissible error in respect of any working standard weight, on verification or re-verification after adjustment, shall be such as is specified in Part I of Third Schedule.

(3) Every working standard metre bar shall conform, as regards material used in construction, and design, to the specifications laid down in Part II of Third Schedule.

(4) The maximum permissible error in respect of any working standard metre bar, on verification or re-verification, shall be such as is specified in Part II of Third Schedule.

(5) Every working standard capacity measure shall conform, as regards denomination, material used in construction, and design, to the specifications laid down in Part III of
Third Schedule.

(6) The maximum permissible error in respect of any working standard capacity measure, on verification or re-verification after adjustment, shall be such as is specified in Part III of Third Schedule.

6. Power to specify any other reference, secondary or working standard

(1) Any other reference standard, or secondary standard, or working standard shall conform as regards the denomination, material used in construction, and design, to such specifications as the Central Government may, from time to time, by notification, specify.

(2) The maximum permissible error in relation to such other reference standard, or secondary standard, or working standard shall be such as the Central Government may, from time to time, by notification, specify and different maximum permissible errors may be specified in relation to different types of reference standards, or secondary standards, or working standards.

CHAPTER III
SPECIFICATIONS OF STANDARD EQUIPMENT

7. Reference standard balances

(1) A set of reference standard balances shall be maintained at every place where the reference standard weights are kept for the purpose of verification of secondary standards.

(2) The number, types and specifications of such balances shall be as are specified in Part I of Forth Schedule.

(3) Every reference standard balance shall be verified at least once in six months and shall be adjusted, if necessary, to make it correct within the limits of sensitivity and other metrological qualities as are specified in Part I of Forth Schedule.

8. Secondary standard balances

(1) A set of secondary standard balances shall be maintained at every place where secondary standard weights are kept for the purpose of verification of working standards.

(2) The number, types and specifications of such balances shall be as are specified in Part II of Forth Schedule.

(3) Every secondary standard balance shall be verified at least once in one year and shall be adjusted, if necessary, to make it correct within the limits of sensitivity and other metrological qualities as are specified in Part II of Forth Schedule.

9. Working standard balances

(1) A set of working standard balances shall be maintained at every place where working standard weights are kept for the purpose of verification of weights intended to be used for transaction, or protection, or industrial production.

(2) The number, types and specifications of such balances shall be as are laid down in Part III of Forth Schedule.

(3) Every working standard balance shall be verified at least once in a year and shall be adjusted, if necessary, to make it correct within the limits of sensitivity and other metrological qualities as are specified in Part III of Forth Schedule.

10. Power to specify the standard equipment

The Central Government may, by notification, specify such other standard equipment as it may think necessary to carry out the provisions of the Act and every such standard equipment shall conform, as regards the metrological qualities, to such specifications as the Central Government may, in the same notification or subsequent notification, specify.

CHAPTER IV
WEIGHTS OR MEASURES AND WEIGHING AND MEASURING INSTRUMENTS

11. Weights

(1) Save as otherwise provided in these rules, every weight used or intended to be used—

(a) in any transaction, or

(b) for protection,

shall conform, as regards physical characteristics, configuration, constructional details, materials, performance, tolerances and such other details, to the corresponding specifications laid down for such weight in Fifth Schedule.

(2) The maximum permissible error in respect of such weight shall be such as is specified in Fifth Schedule.

(3) Nothing in this rule shall apply to the product of an industry which is required, by or under any law for the time being in force, to conform to any other specifications with regard to the matters specified in sub-rule (1) or sub-rule (2), if, under such law, the product is required to conform to the specifications laid down by the International Organisation of Legal Metrology with regard to the matters aforesaid.

12. Measures (other than measuring instruments)

(1) Every measure used or intended to be used for—

(a) any transaction, or

(b) protection,

shall conform, as regards physical characteristics, configuration, constructional details, materials, performance, tolerances and such other details, to the corresponding specifications laid down for such measure in Sixth Schedule.

(2) The maximum permissible error in such measure shall be such as is specified in the corresponding specifications laid down for such measure in Sixth Schedule.

13. Weighing and measuring instruments

(1) Every weighing instrument used or intended to be used—

(a) in any transaction, or

(b) for protection,

shall conform, as regards physical characteristics, configuration, constructional details, materials, performance, tolerances and such other details, to the corresponding specifications laid down for such weighing instrument in Seventh Schedule:

(2) Every measuring instrument used or intended to be used—

(a) in any transaction, or

(b) for protection,

shall conform, as regards physical characteristics, configuration, constructional details, materials, performance, tolerances and such other details, to the corresponding specifications laid down for such measuring instrument in Eight Schedule.

(3) The maximum permissible error on such weighing or measuring instrument shall be such as is specified in the corresponding specifications laid down for such weighing or measuring instrument in Schedule VII or as the case may be in Eight Schedule.

14. Procedure for carrying out calibration of vehicle tanks, etc.

The procedure for carrying out calibration of vehicle tanks, etc. shall be as is specified in Ninth A Schedule.

CHAPTER V
IMPORT OF WEIGHTS AND MEASURES

15. Registration of importer

(1) Every manufacturer or dealer of weight or measure who intends to import any weight or measure shall apply to the Director, through the Controller of the State in which he carries on such business, for registration of his name as importer in the form specified in Tenth Schedule.

(2) Every application received by the Controller under sub-rule (1) or sub-rule (2), as the case may be, shall be forwarded by him to the Director with a report as to the antecedents and technical capabilities of the applicant.

(3) Nothing in this rule shall take away or abridge the right of any person referred to in sub-rule (2) to carry on the business of importing of any weight or measure until he has been informed by the Director in writing that he cannot be registered as an importer, and on receipt of such letter he shall stop forthwith the import of any weight or measure:

PROVIDED that registration of a person carrying on, at the commencement of these rules, the business of importing weights or measures shall not be refused except after giving him a reasonable opportunity of showing cause against the proposed action.

(4) Every application for the registration of an importer shall be submitted to the Director, in the manner aforesaid, together with the fee specified in Twelfth Schedule, at least one month before the date on which import is proposed to be made.

(5) The registration of a person as an importer shall remain effective for a period of five years from the date of such registration.

(6) On the expiry of the period of registration as an importer, the Director may, on the application of the registered importer and on payment of the prescribed fee, renew registration for a like period.

(7) The registration or renewal of the registration of a person as an importer may be suspended or revoked before the expiry of the period of validity thereof, if the Director is satisfied after an inquiry, and after giving to the person concerned a reasonable opportunity of being heard, that any statement made by such person in the application for registration or renewal of registration was false or incorrect in material particulars or that such person has contravened any provision of the Act or rules made there under or any term or condition of such registration.

16. Conditions, etc. for manufacture of a weight or measure exclusively for export

(1) The provisions of this rule shall apply to weights or measures which are made or manufactured exclusively for the purpose of export.

(2) No non-standard weight or measure shall be made or manufactured by any person unless he has obtained the previous permission from the Central Government:

(3) Every person intending to manufacture any non-standard weight or measure for the purpose of export shall make an application for permission to the Central Government on payment of a fee of rupees five hundred for such permission authorising him to manufacture such weight or measure and shall in such application indicate—

(a) his name and full address;

(b) location of the factory in which such weight or measure is proposed to be manufactured;

(c) description of weight or measure proposed to be manufactured;

(d) documentary or other evidence indicating the existence of a firm contract for the export aforesaid or where there is no such firm contract for export, documentary or other evidence indicating that there is likely to be a demand for the export of non-standard weight or measure.

(4) The Central Government shall, if it is satisfied from the documentary or other evidence produced by the applicant or otherwise that the applicant intends to manufacture non-standard weight or measure for export, grant the permission authorising him to manufacture such weight or measure:

PROVIDED that the Central Government may, if it is satisfied that the applicant has contravened any of terms and conditions of the permission or that weights or measures manufactured by the applicant have found their way into the Indian market or that the applicant had made any statement in his application for the permission which is false in material particulars or he had concealed some material particulars, cancel the permission:

PROVIDED FURTHER that no permission shall be cancelled except after giving to the applicant a reasonable opportunity of showing cause against the proposed action.

(5) Every permission granted under sub-rule (4) shall remain valid for a period of one year and shall be renewed for a like period on payment of a like fee unless the Central Government is satisfied that the applicant has made any statement in his application which is false in material particulars or that he had concealed some material particulars or had contravened any provision of the Act or any rule made there under:

PROVIDED that no order for the refusal to renew a licence shall be made by the Central Government except after giving the applicant a reasonable opportunity of showing cause against the proposed action.

(6) Every person who is granted permission under this rule shall submit to the Central Government, at the end of the calendar year, a statement as to the quantity of the non-standard weights and measures exported by him and the particulars of the person to whom such export has been made.

17. Prohibition on sale of non-standard weight or measure within the country

No non-standard weight or measure made or manufactured exclusively for export shall be sold or otherwise distributed within the territory of India.

18. Maintenance of record in relation to non-standard weight or measure

Every person who makes or manufactures any non-standard weight or measure for export shall maintain a monthly record of the number of such non-standard weights or measures manufactured by him, number of weights or measures already exported by him, and number of weights or measures in stock or under production. The record so maintained shall be open to inspection by any officer authorised by the Central Government in this behalf.

19. Sample checking of weight and measure

(1) Standard weights or measures which are intended for export shall not ordinarily require any verification and stamping, but if the party to whom the export is to be made so requires, a sample checking of such weight or measure shall be made by such agency as the Central Government may specify in this behalf, and thereupon the agency so specified shall, after checking the weight or measure, issue a certificate indicating whether or not such weight or measure conforms to the requirements of the Act and the rules made there under.

(2) The weight or measure to be checked as sample under this rule shall be selected at random and proper records shall be maintained with regard to the sample checking so made.

(3) The Central Government shall, while specifying the agency for checking the weight or measure, ensure that the agency completes the checking well in time so that the export of the weight or measure is not delayed by reason of such checking.

20. Checking of non-standard weights and measures sample which are to be exported

(1) Non-standard weight or measure, which is made or manufactured exclusively for export, shall not ordinarily require any verification and stamping, but if the party to whom the export is to be made so requires, a sample checking of such weight or measure shall be made by such agency as the Central Government may specify in this behalf; and thereupon the agency so specified shall, after checking the weight or measure, issue a certificate indicating whether or not such weight or measure conforms to the specifications given by the party to whom the export is to be made or, where the party aforesaid has not given any specification, whether the weight or measure conforms to the specifications laid down by the manufacturer.

(2) The weight or measure to be checked as sample under this rule shall be selected at random and proper records shall be maintained with regard to the sample checking so made.

(3) The fee for checking of any non-standard weight or measure shall be—

(i) if it is similar to any standard weight or measure, equal to the fee leviable for the verification and stamping of such standard weight or measure; and

(ii) where such non-standard weight or measure is not similar to any standard weight or measure, the Central Government may specify such amount as fees as is commensurate with the labour involved in checking the non-standard weight or measure.

(4) The Central Government shall, while specifying the agency for checking the non-standard weight or measure, ensure that the agency completes the checking well in time so that the export of such weight or measure is not delayed by reason of such checking.

CHAPTER VI

NON-STANDARD WEIGHT OR MEASURE TO BE USED FOR SCIENTIFIC INVESTIGATION OR RESEARCH

21. Permission to get manufactured non-standard weight or measure for scientific investigation or research

Where the manufacture of any non-standard weight or measure is needed exclusively for the purpose of scientific investigation or research, the person needing such non-standard weight or measure shall make an application to the Central Government for permission to get such non-standard weight or measure manufactured and on receipt of such application, if the Central Government is satisfied that the manufacture of such non-standard weight or measure is needed for the purpose aforesaid, it may authorise the applicant to get the non-standard weight or measure needed by him manufactured by such manufacturer as he may think fit, and thereupon, it shall be lawful for such manufacturer to manufacture the said non-standard weight or measure in accordance with the specifications given by the applicant.

Explanation: For the purpose of this rule, a non-standard weight or measure means a weight or measure which is, or is proposed to be, manufactured in accordance with any unit of weight or measure, other than standard unit of weight of measure specified by or under the Act.

CHAPTER VII
MISCELLANEOUS

22. The manner of disposal of goods seized under this Act/rule

(1) Where any goods seized under sub-section (3) of section 15 are subject to speedy or natural decay, the Director or any person authorised by him or Controller and other Legal Metrology Officers in this behalf shall have the goods weighed or measured on a verified weighing or measuring instrument available with him or near the place of seizure and enter the actual weight or measure of the goods in a form specified by the Director for this purpose and shall obtain the signature of the trader or his agent or such other person who has committed the offence. The goods in question shall, after such weighing or measuring is returned to the trader or the purchaser as the case may be:

PROVIDED that if the trader or his agent or the other person (who has committed the offence) refuses to sign the form, the Director or the person authorised by him in this behalf shall obtain the signature of not less than two persons present at the time of such refusal by the trader or his agent or other person.

(2) Where the goods seized under sub-section (1) are contained in a package and the package is false or does not conform to the provisions of the Act or any rules made there under and the goods in such package are subject to speedy or natural decay, the Director or any person authorised by him or Controller and other Legal Metrology Officers in this behalf, so far as may be, may dispose of the goods in such package in accordance with the provisions of sub-rule (1).

(3) Where the goods seized under sub-rule (1) are not subject to speedy or natural decay, the Director or any person authorised by him or Controller and other Legal Metrology Officers in this behalf may retain the package for the purpose of prosecution under this Act after giving the trader or his agent or the other person (who has committed the offence) a notice of such seizure.

23. Time within which unverified weight and measure to be verified and stamped

No unverified weight or measure, seized under sub-section (3) of section 15, shall be forfeited if the person, from whom such weight or measure was seized, agrees to get the same verified and stamped within a period of ten days or such extended period from the date of such seizure; and for this purpose, the person making the seizure of such weight or measure shall afford a reasonable opportunity by returning such weight or measure exclusively for the verification and stamping.

24. Register and reports to be maintained by persons referred to in section 17 of the Act

(1) Every person referred to in sub-section (1) of section 17 shall maintain a register in the appropriate form set out in Eleventh Schedule.

(2) Notwithstanding anything contained in sub-rule (1), if the Director is of the opinion that having regard to the nature or volume of the business carried on by any maker, manufacturer, dealer or repairer, it is necessary to do so, he may, by order, exempt any such maker, manufacturer, dealer or repairer from the operation of that sub-rule.

25. Scale of fee

The scale of fees to be collected for the service specified in column (2) of Twelfth Schedule shall be at the rate specified in column 3 of the said Schedule.

26. Use of regional languages

Any legend or denomination specified in any Schedule to these rules, which is required to be indicated on any weight or measure in English, or in Devanagri script, may also be indicated (in addition to English or Devanagri) on such weight or measure in such regional language as the manufacturer may consider to be practicable.

27. Periodical verification of weights or measures –

(1) Every weight or measure used or intended to be used in any transaction or for protection of living beings or things in clause (k) of section 2 shall be verified and stamped by the legal metrology officer in the State in which such weight or measure is put to use and shall be re-verified and stamped at periodical intervals.

(2) The re-verification shall be carried out on the completion of a period of,-

(a) twenty four months for all weights, capacity measures, length measures, tape , beam scale and counter machine,

(b) sixty months for storage tanks, and

(c) twelve months for all weight or measure including tank lorry other than that mentioned in clauses (a) & (b).

(3) Notwithstanding anything contained in sub-rule (2) every weight or measure which has been verified and stamped in situ shall, if it is dismantled and re-installed before the date on which the verification falls due shall be duly re-verified and stamped, before being put into use.

(4) Notwithstanding anything contained in sub-rule (1) every weight or measure which has been verified and stamped shall, if it is repaired before the date on which the verification falls due shall be duly re-verified and stamped before being put into use.

28. Qualifications of Legal Metrology Officer:

(1) No person shall be appointed as Legal Metrology Officer unless he –

(a) is a graduate of a recognized university in Science (with physics as one of the subjects), technology or engineering or holds a recognized diploma in engineering with three years professional experience; and

(b) is able to speak, read and write at least one of the regional languages of the State.

(2) Nothing in sub-rule (1) shall apply to officials who have been working as Legal Metrology officer and are also eligible for promotion to the next higher grade of Legal Metrology officer on the date of commencement of these rules.

(3) The person appointed to the post of Legal Metrology Officer shall have to successfully complete the basic training course at the Indian Institute of Legal Metrology, Ranchi before his posting.

(4) The Central Government may, in consideration of the practical difficulties faced by the State Government and on its recommendation, relax the qualification specified in sub-rule (1) for the post of legal metrology officers for that State.

29. Nomination of Director by a Company under the Act:

Every company shall inform the Director (Legal Metrology) or the concerned Controller or his authorized officer, by notice in duplicate, in the format specified in Thirteenth Schedule containing the name and address of its Director after obtaining his consent in writing, who has been nominated by the company under sub-section (2) of section 49 to be in-charge of and be responsible for the conduct of business of the company or any establishment, branch or unit thereof.

30. Repeal and savings :- (1) The Standards of Weights and Measures (General) Rules, 1987 (herein under referred to as the said rules) are hereby repealed.

Provided that such repeal shall not affect:

(a) the previous operations of the said rules or anything done or omitted to be done or suffered therein; or

(b) any right, privilege, obligation or liability acquired, accrued or incurred under the said rules; or

(c) any penalty, forfeiture or punishment incurred in respect of any offence committed against the said rules; or

(d) any investigation, legal proceedings or remedy in respect of any such right, privilege, obligation, liability, penalty, forfeiture or punishment as aforesaid.

And any such investigation, legal proceedings or remedy may be instituted, continued or enforced and any such penalty, forfeiture or punishment may be imposed as if the said rules had not been rescinded.

(2) Notwithstanding such repeal anything done or any action taken or purported to have been done or taken including approval of letter, exemption granted, fees collected, any adjudication, enquiry or investigation commenced, license and registration of manufacturers, dealers, importers of weights and measures, non-standard weights and measures or show cause notice, decision, determination, approval, authorisation issued, given or done under the said rules shall if in force at the commencement of the said rules continue to be in force and have effect as if issued, given or done under the corresponding provisions of these rules.

(3) The provisions of these rules shall apply to any application made to the Central Government or as the case may be the State Government under the said rules for registration of manufacturers, importers, dealers, repairers of weights and measures pending at the commencement of these rules and to any proceedings consequent thereon and to any registration granted in pursuance thereof.

(4) Any legal proceeding pending in any court under the said rules at the commencement of these rules may be continued in that court as if these rules had not been framed.

(5) Any appeal preferred to the Central Government or as the case may be the State Government under the said rules and pending shall be deemed to have been made under the corresponding provisions of these rules.

INDEX OF SCHEDULES TO THE STANDARDS OF

Legal Metrology (GENERAL) RULES

FIRST SCHEDULE
PART I

Reference Standard Weights

PART II

Reference Standard Metre Bar

SECOND SCHEDULE

PART I Secondary Standard Weights
PART II Secondary Standard Metre Bar
PART III Secondary Standard Capacity Measures

THIRD SCHEDULE

PART I

Standard Weights

PART II

Working Standard Metre Bar

PART III Working Standard Capacity Measures
FOURTH SCHEDULE
PART I Reference Standard Balances
PART II Secondary Standard Balances
PART III Working Standard Balances
FIFTH SCHEDULE
PART I

Weights (Other than Carat Weights)

PART II

Carat Weights

PART III Standard Weights for testing of High Capacity Weighing Machine
SIXTH SCHEDULE
PART I

Liquid Capacity Measures

PART II

Dispensing Measures

PART III Liquor Measures
PART IV Length Measures (Non-Flexible)
PART V Folding Scales
PART VI

Fabric or Plastic Tape Measure

PART VII Steel Tape Measures
PART VIII Surveying Chains
PART IX Tapes for Use in Measurement of Oil Quantities
SEVENTH SCHEDULE

Heading A

SPECIFICATIONS FOR NON-AUTOMATIC WEIGHING INSTRUMENTS

Heading B

PART I

Beam Scales

PART II

Counter Machines

Heading C

Specifications of Automatic Rail Weighbridge

Heading D

Specifications of Automatic Gravimetric Filling Instrument

EIGHTH SCHEDULE

SPECIFICATIONS FOR MEASURING INSTRUMENTS

PART I

Volumetric Container Filling Machines

PART II Bulk Meters
PART III Water Meters
PART IV Meters for Liquids (Other than Water)
PART V Volumetric Container Type Liquid Measuring Device
PART VI Clinical Thermometer – Solid Stem Type
PART VII

Monometers of Instruments for Measuring Arterial Blood Pressure (Sphygmomanometers)

PART VIII

Taximeter

PART IX

COMPRESSED GASEOUS FUEL (CNG) MEASURING SYSTEMS FOR VEHICLES

NINETH SCHEDULE

PROCEDURE FOR CARRYING OUT CALIBRATION OF VEHICLE TANKS ETC.

PART I Calibration of Vehicle Tanks for Petroleum Products and other Liquids
PART II Method for Calibration of Vertical Oil Storage Tanks
PART III Method for Computation of Capacity Tables for Vertical Oil Storage Tanks.

TENTH SCHEDULE

APPLICATION FORM FOR REGISTRATION OF IMPORTER OF WEIGHTS AND MEASURES

ELEVENTH SCHEDULE

REGISTER TO BE MAINED BY THE MANUFACTURERS/DEALER/REPAIRER OF WEIGHTS AND MEASURES

TWELTH SCHEDULE

SCALE OF FEE

FIRST SCHEDULE

DENOMINATION, MATERIALS, SHAPE AND PERMISSIBLE ERRORS,
IN RESPECT OF REFERENCE STANDARDS |
[ Rule 3 ]
PART I
REFERENCE STANDARD WEIGHTS

1. Denominations

Kilogram series Gram series Milligram series
5
500
500
2
200
200
2
200
200
1
100
100
 
50
50
 
20
20
 
20
20
 
10
10
 
5
5
 
2
2
 
2
2
 
1
1

2. Materials

(a) Weights of 5 kg to 1g shall be made from admiralty bronze (88 Cu, 10 Sn, 2 Zn), nickel chromium alloy (80 Ni, 20 Cr) or austenitic stainless steel (25 Ni, 20 Cr) or (20 Ni, 25 Cr).

(b) Weights of 500 mg to 10 mg shall be made from wire of either pure platinum, nickel chromium alloy (80 Ni, 20 Cr) or austenitic stainless steel (25 Ni, 20 Cr) or (20 Ni, 25 Cr).

(c) Weights of 5 mg to 1 mg shall be made of aluminium wire. Copper, silicon and zinc contained as impurities in aluminium shall not exceed 0.3 per cent in the aggregate.

Note: The material used for all the weights shall be non-magnetic and it shall be ensured that the finished weights are also practically non-magnetic.

3. Shape and finish

(a) For kilogram and gram series—

Integral cylindrical body with knob rounded at top.

(b) For milligram series—

The weights shall be made from the wire having five segments for 500, 50, 5 mg weights, two segments for 200, 20, 2 mg weights and one segment for 100, 10, and 1 mg weights. One end of the wire shall be bent at right angles for the purposes of lifting it with a pair of forceps.

(c) The denominations shall be marked only on kilogram and gram series weights.

(d) The entire surface of the weights, including their base and corners shall be free from any roughness and the surface of the weights when inspected visually shall not show any porosity and shall have a mirror finish.

4. Maximum permissible errors

Denomination 5Permissible error + mg
5 kg
7.5
2 kg
3.0
1 kg
1.5
500 g
0.75
200 g
0.30
100 g
0.15
50 g
0.10
20 g
0.080
10 g
0.060
5 g
0.050
2 g
0.040
1 g
0.030
500 mg
0.025
200 mg
0.020
100 mg
0.015
50 mg
0.012
20 mg
0.010
10 mg
0.008
5 mg
0.006
2 mg
0.006
1 mg
0.006

5. Protective and carrying case

(a) These weights shall be stored in their boxes made from teakwood or any other suitable non-corrosive material with proper housing lined with chemically neutral velvet, chamois leather or soft plastic material. Wood used in such boxes shall be reasonably free from resins and volatile materials. Glue shall not be used for fixing velvet or such other material. The weights shall be housed in such a manner so as to avoid their movement during transit.

(b) Each milligram weight shall be provided with a separate housing. A covering glass or a sheet of any other transparent and non-reactive and non-corrosive material shall be provided so as to ensure that these weights are not dislocated during transit.

(c) A suitable device for lifting the kilogram and gram weights covered with chamois leather or other suitable material shall be provided. A pair of forceps capable of lifting easily milligram weights shall also be provided.

6. Inscription

The boxes containing the weights shall have the following inscriptions:

(a) The words ‘Reference Standards Weights'

(b) The identification number of such boxes,

(c) The name of the manufacturer,

(d) The material used for weights,

(i) kilogram and gram series,

(ii) milligram series,

(e) The year of manufacture,

(f) The verification mark of the NPL.

PART II
REFERENCE STANDARD METRE BAR

1. Material

The Reference Standard Metre Bar (hereafter called metre bar) shall be manufactured from 58 per cent nickel-steel.

2. Shape and dimensions

(a) The metre bar shall be of H-section, approximately 25 mm x 25 mm (as per Figure 1)

(b) The overall length of the metre bar shall be 1030 + 1 mm and the graduated length shall be 1008 mm.

(c) Ungraduated space of 11 mm shall be left after the last graduation mark.

3. Finish

The graduated surface shall be bright highly polished, and free from surface irregularities in the neighbourhood of the graduation marks.

4. Graduations

(a) The main scale shall be situated on the neutral plane and shall be graduated in millimetres throughout from 0 to 1000 mm.

(b) The main scale shall also have one additional mm mark before 0 and another after 1000 mm mark.

(c) An additional fine scale shall also be provided at each end of the main scale for calibrating a micrometre microscope. This fine scale shall consist of ten 0.1 mm graduations (1 mm sub-divided into 10 parts) and shall be situated before the first graduation mark after leaving a blank space of 2 mm and also after the last mark with the same blank spacing.

(d) The graduation marks shall be well-defined, of symmetrical section and have clean edges.

(e) The width of graduation marks shall be between 8 and 10 micrometres. This width shall be constant to within ten per cent over the length of each mark between the longitudinal setting lines.

(f) The graduation marks shall not differ in width one from another by more than + 10% of the average width of all the marks.

(g) The graduation marks shall be parallel to one another to within one micrometre between the longitudinal setting lines.

(h) The graduation marks shall be square to the scale axis to within ten minutes of arc.

(i) The length of graduation marks shall be as follows:—

—2 mm for half cm marks.

—1 mm for mm marks.

The marks shall be disposed equally on either side of an imaginary centre line.

(j) The lengths of the graduation marks on the two fine scales referred to in 4(c) shall be as follows:—

—3 mm for first and last mark.

—2 mm for 0.5 mm marks.

—1 mm for 0.1 mm marks.

(k) The Bessel points shall be indicated by two vertical lines marked on either external side of the metre bar. The Bessel points shall be 571 mm apart, and shall be disposed equally on either side of the 500 mm mark.

(l) No figures or numerals shall be marked on the surface of the main scale.

(m) When supported at the marked Bessel points, the graduated surface shall be flat to within 0.05 mm, i.e. all points on the surface shall be between two parallel planes 0.05 mm apart.

5. Auxiliary scale

(a) An auxiliary scale shall be marked on one of the top edges of the metre bar.

(b) The auxiliary scale shall consist of 1000 marks corresponding to the marks of the main scale.

(c) The marks of the auxiliary scale shall be collinear (i.e., passing through the same vertical planes) with the graduation marks of the main scale to within
+ 0.1 mm.

(d) The width of graduation marks shall be not more than 100 micrometres and shall be clearly visible to the naked eyes having normal vision.

(e) The length of the graduation marks shall be :

—2.5 mm for cm marks.

—2.0 mm for half cm marks.

—1.5 mm for mm marks.

One of the ends of all the marks shall lie on a straight line.

(f) The centimetre graduation marks shall be numbered in the increasing order of numeration.

(g) The height of the numerals and the letters shall be approximately 3 mm.

6. Setting lines

(a) A pair of longitudinal setting lines shall transverse the graduation marks and shall be parallel to the scale axis to within one minute of arc.

(b) The two longitudinal lines shall be disposed symmetrically on either side of the centre of the graduation marks.

(c) The separation of the longitudinal setting lines shall be 0.2 mm and their width shall be in between 8 and 10 micrometres.

(d) Each longitudinal setting line shall be straight to within 30 micrometres.

(e) The longitudinal setting lines shall be parallel to each other to within 50 micrometres.

7. Maximum permissible error

(a) When the metre bar is supported on its marked Bessel points, the errors in length between any two graduation marks of the main scale at the temperature of 20 o C, shall not exceed 0.010 mm.

(b) In the case of the fine scales, the error between any two 0.1 mm marks shall not exceed 0.005 mm.

8. Inscription

The metre bar shall bear the following inscription:

(a) the words “REFERENCE STANDARD METRE BAR”,

(b) the identification number of the metre bar,

(c) the verification mark of the NPL, after the first calibration and marks of subsequent verification and marks of subsequent verification to be made on the plate of the carrying case of the metre bar,

(d) the name of the manufacturers,

(e) the material of the metre bar,

(f) the words, figures and letter “STANDARD AT 20 o C”,

(g) the year of manufacture.

9. Protective and carrying case

(a) The standard metre bar shall be housed in a case made from suitable material and provided with a handle, lined internally with velvet, a plastic material or any other material and in such a way that the metre bar is not likely to be damaged, particularly by shocks or corrosion.

(b) The case shall have affixed on it a plate bearing the inscription “REFERENCE STANDARD METRE BAR” and the identification number.

SECOND SCHEDULE
DENOMINATIONS, MATERIALS, SHAPE AND PERMISSIBLE ERRORS
IN RESPECT OF SECONDARY STANDARDS
[ Rule 4 ]
PART I
SECONDARY STANDARD WEIGHTS

1. Denominations

Kilogram series
Gram series
Milligram series
10
500
500
5
200
200
2
200
200
2
100
100
1
50
50
20
20
20
20
10
10
5
5
2
2
2
2
1
1

2. Materials

(a) Weights of 10 kg to 1 g shall be made from admiralty bronze (88 Cu, 10 Sn, 2 Zn), or nickel-chromium alloy (80 Ni, 20 Cr) or austenitic stainless steel (20 Ni, 25 Cr) or (25 Ni, 20 Cr).

(b) Weights of 500 mg to 50 mg shall be made from cupro-nickel (75 Cu, 25 Ni), or nickel chromium alloy (80 Ni, 20 Cr), or austenitic stainless steel (20 Ni, 25 Cr), or (25 Ni, 20 Cr).

(c) Weights of 20 mg to 1 mg shall be made of aluminium sheets. Copper, silicon and zinc contained as impurities in aluminium shall not exceed 0.3 per cent in the aggregate.

3. Shape and finish

(a) For kilogram and gram series—Integral cylindrical body with knob flattened at the top. Weights of 10 kilogram to 100 gram (both inclusive) shall have adjusting devices.

(b) For milligram series—the weights shall be in the form of square sheets, one of the corners being bent at right angle.

(c) The denominations shall be marked only on kilogram and gram series weights.

(d) The entire surface of the weights, including their base and corners shall be free from any roughness and the surface of the weights, when inspected visually, shall not show any porosity and shall have a mirror polish appearance.

4. Maximum permissible error

Denomination
Permissible error + mg
10 kg
50
5 kg
25
2 kg
10
1 kg
5
500 g
2.5
200 g
1.0
100 g
0.5
50 g
0.30
20 g
0.25
10 g
0.20
5 g
0.15
2 g
0.12
1 g
0.10
500 mg
0.08
200 mg
0.06
100 mg
0.05
50 mg
0.04
20 mg
0.03
10 mg
0.025
5 mg
0.02
2 mg
0.02
1 mg
0.02

5. Protective and carrying case

(a) These weights shall be stored in their boxes made from teakwood or any other suitable non-corrosive material with proper housing lined with chemically neutral velvet, chamois leather or soft plastic material. Wood used in such boxes shall be reasonably free from resins and volatile materials. Glue shall not be used for fixing velvet or such other material. The weights shall be housed in such a manner so as to avoid their movement during transit.

(b) Each milligram weight shall be provided with a separate housing. A covering glass or a sheet of any other transparent, non-reactive and non-corrosive material shall be provided so as to ensure that these weights are not dislocated during transit.

(c) A suitable device for lifting the kilogram and gram weights, covered with chamois leather or other suitable material, shall be provided. A pair of forceps capable of lifting easily milligram weights shall also be provided.

6. Inscription

The boxes containing the weights shall have the following inscriptions:—

(a) the words ‘SECONDARY STANDARD WEIGHTS',

(b) the identification number of the secondary standard weights,

(c) the name of the manufacturer,

(d) the material used for weights—

(i) kilogram & gram series

(ii) milligram series,

(e) the year of manufacture,

(f) the mark of verification.

PART II
SECONDARY STANDARD METRE BAR

1. Material

The secondary standard metre bar (hereafter called metre bar) shall be manufactured from 58 per cent nickel-steel.

2. Shape and dimensions

(a) The metre bar shall have a rectangular cross-section with dimensions 30mm x 15mm approximately.

(b) The top surface shall have two rectangular grooves along its length (as per Figure 2).

(c) The overall length of the measure shall be 1030 + 1 mm and the graduated length shall be 1010 mm.

(d) Ungraduated space of 10 mm shall be left after the last graduation mark.

3. Finish

The graduated surface shall be bright, highly polished and free from surface irregularities in the neighbourhood of the graduation mark.

4. Graduations

(a) The metre bar shall be graduated in millimetres throughout from 0 to 1000 mm.

(b) A length of 10 mm before the zero graduation mark shall also be graduated in millimetres.

(c) The scale shall be regular. The width of the graduation marks shall be between thirty and fifty micrometres.

(d) The width of the graduation marks shall be uniform to within + ten per cent of the average width of all the marks.

(e) Each graduation marks shall be straight to within ten micrometres over its length.

(f) The graduation marks shall be parallel to one another to within ten micrometres.

(g) The graduation marks shall be square to the scale axis to within twenty minutes of arc.

(h) The graduation marks representing centimetres shall be longer than those representing half centimetres and the graduation marks representing half centimetres shall be longer than those representing millimetres.

(i) The length of the graduation marks shall be not less than:

—2 mm for mm marks.

—3 mm for half cm marks.

—4 mm for cm marks.

These marks shall be disposed equally on either side of an imaginary centre line defined by the two setting lines.

(j) There shall be two short longitudinal setting lines each of 5 mm in length which shall be drawn leaving a blank space of 2 mm, the one before the first and the other after the last graduation mark. The longitudinal lines shall be on a straight line which represent the imaginary central line and the departure from the central line shall be not more than 0.1 mm.

(k) When supported on the Bessel points or on a flat surface the graduated surface shall be flat to within 0.05 mm, i.e. all the points on the surface shall be between two parallel planes 0.05 mm apart.

5. Auxiliary scale

(a) Auxiliary scale shall be marked on one of the top edges of the metre bar.

(b) The auxiliary scale shall consist of centimetre and half centimetre marks corresponding to the marks of the main scale.

(c) The marks of the auxiliary scale shall be collinear (passing through the same vertical planes) with the graduations of main scale to within + 0.1 mm.

(d) The width of the graduation marks shall be not more than one hundred micrometres.

(e) The graduation marks representing centimetres shall be longer than those representing half centimetres.

(f) The length of the graduation marks shall be not less than:

—3 mm for cm marks, and

—2 mm for half cm marks.

One of the ends of the marks shall lie on a straight line.

(g) The centimetre graduation marks shall be numbered in the increasing order of numeration.

(h) The height of the numerals and the letters shall be approximately 3 mm.

6. Maximum permissible error

The error on the length between any two graduation marks on the secondary standard metre bar, at the standard temperature of 20 o C, shall not exceed the value “e” calculated according to the following formula:

e = + (25 + L/40) micrometres

Where L is the nominal length in millimetres of that part of the metre bar between the two graduation marks, the error on which is being determined. The calculated value of “e” shall be rounded to the nearest integer.

7. Inscription

The metre bar shall bear the following inscriptions :

(a) the words “SECONDARY STANDARD METRE BAR”,

(b) an identification number of the secondary standard metre bar,

(c) the name of the manufacturer,

(d) the material of the metre bar,

(e) the words, figures and letter “STANDARD AT 20 o C”,

(f) the year of manufacture,

(g) the mark of verification on the plate of the carrying case of the metre bar.

8. Protective and carrying case

(a) The metre bar shall be housed in a case made from suitable material and provided with a handle, lined internally with velvet, a plastic material or any other material, and in such a way that the measure is not likely to be damaged, particularly by shocks or corrosion.

(b) The case shall have affixed on it a plate bearing the inscription “SECONDARY STANDARD METRE BAR” and the identification number.

Note : The existing secondary standard metre bars may differ in minor details in regard to setting lines and inscriptions, etc.

 

PART III
SECONDARY STANDARD CAPACITY MEASURES

1. Denominations

Litre series (1)

Millilitre series (ml)

5
500
2
200
1
100
50
20

Note : 1 litre = 1 dm 3 = 0.001 m 3 ; 1 ml= 1 cm 3

2. Material

Secondary standard capacity measures shall be cast out of admiralty bronze of the same composition as is employed in the case of secondary standard weight.

3. Shape

(a) The secondary standard capacity measure of five litre shall be cylindrical and have its inside diameter equal to the height of the measure. This shall have two handles attached securely to its sides.

(b) The measure of 2l and below shall be of the same shape as above but shall not have any handles.

(c) The denominations of the secondary standard capacity measures shall be engraved on the outside surface.

(d) Each secondary standard capacity measure shall be provided with a specially selected striking glass on the measures and glasses shall be securely packed in velvet lined teakwood boxes.

4. Maximum permissible error

Denomination

Permissible error + ml

5l
2
2l
1
1l
0.8
500ml
0.5
200ml
0.4
100ml
0.3
50ml
0.2
20ml
0.1

5. Protective and carrying cases

These capacity measures shall be stored in their boxes made from teakwood or any other suitable non-corrosive material with proper housing lined with velvet, chamois leather or soft plastic material. Wood used in such boxes shall be reasonably free from resins and volatile materials. Glue may not be used for fixing velvet or such other materials. Each capacity measure shall be housed in such a manner so as to avoid their excessive movement during transit.

Each striking glass of the capacity measure shall be securely housed in proper grooves so as to protect them from breakage during transit.

6. Inscriptions

The boxes containing these capacity measures shall have the following inscriptions:—

(a) the inscription SECONDARY STANDARD CAPACITY MEASURES;

(b) the identification number of secondary standard capacity measures;

(c) the name of the manufacturer;

(d) the year of manufacture;

(e) the mark of verification of proper verification authority.

THIRD SCHEDULE
DENOMINATIONS, MATERIAL, SHAPE AND PERMISSIBLE ERRORS
IN RESPECT OF WORKING STANDARDS
[ Rule 5 ]
PART I
WORKING STANDARD WEIGHTS

1. Denominations

Kilogram series
Gram series
Milligram series
20
500
500
10
200
200
5
200
200
2
100
100
1
20
20
20
20
10
10
50
5
2
2
2
2
1
1

2. Material

(a) Weights of 20 kg to 1 g shall be cast from admiralty bronze (88 Cu, 10 Sn, 2 Zn), or made from cupro-nickel (75 Cu, 25 Ni) or nickel chromium alloy (80 Ni, 20 Cr) or austenitic stainless steel (25 Ni, 20 Cr) or (20 Ni, 25 Cr).

(b) Weights of 500 mg to 100 mg shall be made from admiralty bronze (rolled) (88 Cu, 10 Zn, 2 Sn) sheets or from the sheets of nickel chromium alloy (80 Ni 20 Cr) or austenitic stainless steel (25 Ni, 20 Cr) or (20 Ni, 25 Cr).

(c) Weights of 50 mg to 1 mg shall be made of aluminium sheets. Copper, silicon and iron contained as impurities in the aluminium shall not exceed 0.3 per cent in the aggregate.

3. Shape and finish

(a) Weights of 20 kg and 10 kg shall be cylindrical in shape and shall be cast in two parts, the top part being screwed snugly into the bottom part. The top part shall be cast in the form of a handle for lifting purposes. The two parts after assembly shall be locked by means of a set screw over which the seal of the verifying authority shall be affixed.

(b) Weights of 5 kg to 200 gm, (inclusive shall be cast in two parts, the top part being screwed snugly into the bottom part. The top part shall be cast in the form of a knob for lifting purposes. The two parts, after assembly, shall be locked by means of a set screw, over which the seal of the verifying authority shall be affixed.

(c) Weights of 100 g to 10 g (inclusive) shall be as in (b) above except that there shall be no locking arrangement.

(d) Weights of 5 g to 1 g (inclusive) shall be integral weights with knob.

(e) Weights of 500 mg to 1 mg (inclusive) shall be of square shape with the one of the sides bent at right angles to the flat surface for ease of handling.

(f) The denominations shall be marked on the weights.

(g) The entire surface of the weights, including their base and corners shall be free from roughness.

The surface of the weights, when inspected visually, shall not show any porosity and shall have a mirror polish appearance.

4. Maximum permissible error

The permissible errors in excess and in deficiency shall be as follows:—
Denomination
Permissible error + mg
20 kg
300
10 kg
150
5 kg
75
2 kg
30
1 kg
15
500 g
7.5
200 g
3.0
100 g
1.5
50 g
1.0
20 g
0.8
10 g
0.6
5 g
0.5
2 g
0.4
1 g
0.3
500 mg
0.25
200 mg
0.20
100 mg
0.15
50 mg
0.12
20 mg
0.10
10 mg
0.08
5 mg
0.06
2 mg
0.06
1 mg
0.06

5. Protective and carrying case

(a) These weights shall be stored in their boxes made from teakwood or any other suitable non-corrosive material with proper housing lined with chemically neutral velvet, chamois leather or soft plastic material. Wood used in such boxes shall be reasonably free from resins and volatile materials. Glue shall not be used for fixing velvet or such other material. The weights shall be housed in such a manner so as to avoid their movement during transit.

(b) Each milligram weight shall be provided with a separate housing. A covering glass or a sheet of any other transparent, non-reactive and non-corrosive material shall be provided so as to ensure that these weights are not dislocated during transit.

(c) A suitable device for lifting the kilogram and gram weights, covered with chamois leather or other suitable material, shall be provided. A pair of forceps capable of lifting easily milligram weights shall also be provided.

6. Inscription

The boxes containing the weights shall have the following inscriptions:—

(a) the words ‘WORKING STANDARD WEIGHTS',

(b) the identification number of the working standard weights,

(c) the name of the manufacturer,

(d) the year of manufacture,

(e) the marks of verification.

PART II
WORKING STANDARD METRE BAR

1. Material

The working standard metre bar (hereinafter called metre bar) shall be manufactured from 58 per cent nickel-steel, or austenitic stainless steel, or stainless steel with 13 per cent chromium or pure nickel (minimum purity 99 per cent).

2. Shape and dimensions

(a) The metre bar shall have a rectangular cross section of minimum dimensions 20 mm x 10 mm. The existing cross-section with dimensions 30 mm x 15 mm shall be preferred.

(b) The overall length of the metre bar shall be 1030 + 1 mm and the graduated length shall be 1010 mm.

(c) Ungraduated length of 10 mm shall be left after the last graduated marks.

3. Finish

The graduated surface shall be bright, nicely polished and free from surface irregularities in the neighbourhood of the graduation marks.

4. Graduations

(a) The metre bar shall be graduated in millimetre throughout from 0 to 1000 mm on the wider upper surface.

(b) A length of 10 mm before the zero graduation mark shall also be graduated in millimetres.

(c) The scale shall be regular. The thickness of the graduation marks shall be uniform and shall lie between 30 and 80 micrometres.

(d) The width of the graduation marks shall be uniform to within + fifteen per cent of the average width of all the marks.

(e) The graduation marks representing centimetres shall be longer than those representing half centimetres and the graduation marks representing half centimetres shall be longer than those representing millimetres.

(f) Each graduation mark shall be straight to within ten micrometres over its length.

(g) The graduation marks shall be parallel to one another to within ten micrometres.

(h) The length of the graduation marks shall be not less than—

—3 mm for mm marks.

—5 mm for half cm marks.

—8 mm for cm marks.

(i) The centimetres graduation marks shall be numbered in the increasing order of numeration.

(j) The height of the numerals and the letters (symbols) shall be approximately 3 mm.

(k) The graduation marks shall be square to the scale axis to within 30 minutes of arc.

5. Cursor

(a) The errors on the length measure under verification shall be determined by means of a scale marked on a plate, made from transparent material, which is carried by a cursor capable of moving along the length of the metre bar. The plate shall have appropriate and constant dimensions and thickness.

(b) The scale on the plate shall :

(i) either be a length of 9 mm divided into 10 parts thus forming a Vernier scale to read the errors to the nearest of 0.1 mm; or

(ii) one millimetre divided into 10 parts for reading the errors directly to the nearest of 0.1 mm.

(c) The thickness of the graduation marks on the scale shall be less than that of the graduation marks on the metre bar.

(d) The graduation marks on the scale shall be inscribed on the surface facing the graduation marks on the metre bar.

(e) The readings shall be taken by means of a magnifying glass, the magnification of which shall be not less than 5X if the scale is graduated in 0.1 mm and not less than 3X if the scale is of Vernier type.

(f) The cursor shall be such that it would be possible to move it smoothly without jerks, along a straight line from one end of the measure to the other.

(g) A mechanism to raise, lower and laterally move the measure under verification, within a view to putting its graduated surface at a proper level and aligning its zero mark with that of the metre bar shall be provided.

(h) For facilitating the verification of end measures, two vertical stops bearing reference lines shall be provided. The first stop shall be such that its reference line can be aligned with the zero mark of the metre bar. The second stop shall be capable of moving along the entire length of the metre bar.

6. Maximum permissible errors

(a) The error on the length between any two graduation marks on the working standard length measure, at the standard temperature of 20 o C, shall not exceed the value “e” calculated according to the following formula :

e = (50+L/20) micrometres

where L is the nominal length in millimetres of that part of the metre bar between the two graduation marks, the error on which is being determined. The calculated value of “e” shall be rounded to the nearest integer.

(b) The errors on the length between any two graduation lines on the plate shall not exceed + 20 micrometres.

7. Inscription

The metre bar shall bear the following inscription :

(a) the words “WORKING STANDARD METRE BAR”,

(b) identification number of the metre bar,

(c) the name of the manufacturer,

(d) the material of the metre bar,

(e) the words, figures and letter “STANDARD AT 20 o C”,

(f) the year of manufacture.

8. Protective and carrying case

(a) The standard metre bar shall be housed in a case made from suitable material and provided with a handle, lined internally with velvet, a plastic material or any other material and in such a way that the metre bar is not likely to be damaged, particularly by shocks or corrosion.

(b) The case shall have affixed on it a plate bearing the inscription “WORKING STANDARD METRE BAR” and the identification number.

Note : The existing working standard length measure (metre bars) may differ in minor details in regard to inscriptions, etc. on it.

PART III
WORKING STANDARD CAPACITY MEASURES

1. Denomination

Litre series (l)
Millilitre series (ml)
10
500
5
200
2
100
1
50
20

2. Material

Working standard capacity measures shall be pressed out of oxygen free, deoxidized annealed copper sheets of deep drawing quality.

3. Shape

(a) Working standard capacity measure of 10 litres shall be cylindrical and have its inside diameter approximately equal to the height of the measure. This shall have two handles attached securely to its sides.

(b) Working standard capacity measures of 5 litres and below shall be of the same shape as above but shall not have any handles.

(c) The outside of the body of the working standard capacity measures shall be oxidized to give a smooth dull black surface and the inside shall be tinned.

(d) The denominations of the working standard measures shall be engraved on the outside surface.

(e) Each working standard capacity measure shall be provided with specially selected striking glass and the measures and glasses shall be securely packed in velvet lined teakwood boxes.

4. Maximum permissible error

Denomination
Permissible errors in ml ( + ml)
10 litres
8
5 litres
4
2 litres
2
1 litres
1.5
500 ml
1.0
200 ml
0.8
100 ml
0.6
50 ml
0.4
20 ml
0.2

5. Pipette measures

Pipettes of the following description may also be used as working standard measures :

(a) One mark pipettes of capacities 10 ml and 5 ml.

(b) Graduated pipettes of capacities 5 ml graduated at every tenth of ml.

6. Delivery time and maximum permissible errors of pipette measures

Denomination ml Delivery time in seconds Permissible error ( + ml)
Minimum
Maximum
10
15
25
0.04
5
10
20
0.03
5
10
40
0.05
(Graduated)

7. Protective and carrying cases

These capacity measures shall be stored in their boxes made from teakwood or any other suitable non-corrossive material with proper housing lined with velvet, chamois leather or soft plastic material. Wood used in such boxes shall be reasonably free from resins and volatile materials. Glue may not be used for fixing velvet or such other materials. Each capacity measure shall be housed in such a manner so as to avoid their excessive movement during transit.

Each striking glass of the capacity measure shall be securely housed in proper grooves so as to protect them from breakage during transit.

8. Inscriptions

The boxes containing these capacity measures shall have the following inscriptions :

(a) the words “WORKING STANDARD CAPACITY MEASURES”,

(b) the identification number of the capacity measures,

(c) the name of the manufacturer,

(d) the year of manufacture,

(e) the mark(s) of verification of proper verification authority.

FORTH SCHEDULE
SPECIFICATIONS FOR STANDARD EQUIPMENT
[ Rules 7, 8 and 9 ]
PART I

REFERENCE STANDARD BALANCES

1. Every reference standard balance shall be of such robust construction and have such metrological qualities so as to ensure the continued good performance, as indicated in paragraph 2.

2. Sensitivity figure/readability and precision of measurement of every reference standard balance shall be such as to give overall precision of measurement of 1 part in one million for weights from 10 kg to 10 g and + 0.01 mg for weights from 5 g to 1 mg.

PART II
SECONDARY STANDARD BALANCES

1. Every secondary standard balance shall conform as regards capacity, sensitivity figure in mg per division, minimum scale division, variation in sensitivity figure with respect to load and overall accuracy of measurement, to the specifications as indicated below :

Capacity
Sensitivity figure mg/div.
Mini. scale division
Maximum variation in sensitivity figure with respect to load
Minimum overall accuracy of measurement
1
2
3
4
5
20 kg
25
1.5 mm
10 per cent
25 mg in 10 kg
5 kg
7.5
1.0 mm
10 per cent
7.5 mg in 2 kg
1 kg
1.5
1.0 mm
10 per cent
1.5 mg in 500 g
200 g
0.5
1.0 mm
10 per cent
0.5 mg in 50 g
20 g
0.1
1.0 mm
10 per cent
0.1 mg in 5 g
2 g
0.02
0.75 mm
10 per cent
0.02 mg in 1 mg

2. The standard deviation of the 10 consecutive rest points for every secondary standard balance shall not be more than one scale division.

3. The deviation in arm ratio from unity, for every secondary standard equi-arm balance shall not be more than a fraction equal to sensitivity figure divided by full load (both being taken in the same unit).

4. The variation in time periods at different loads for every secondary standard balance shall not be more than 20 per cent.

5. Every secondary standard balance shall be provided with a device so that the contact between the knife-edges and their respective planes is broken when the balance is in arrested position.

6. The secondary standard balance shall, ordinarily, be used for indoor work in laboratories.

7. Every secondary standard balance of digital type shall conform as regards value of verification scale interval as given below:—

Capacity
Maximum value of verification scale interval Type of weights to be verified
20 kg
1 mg
20 kg to 500 g
200 g
0.01 mg
200 g to 1 mg

PART III
WORKING STANDARD BALANCES

1. Working standard balances may be of the following two types:—

(a) Equi-arm types balances;

(b) Digital type balances.

2. Every working standard balance of equi-arm type shall conform, as regards capacity, sensitivity figure, maximum variation in sensitivity figure with respect to load and maximum overall inaccuracy of measurement to the specification as indicated below—

Capacity
Max. sensitivity figure/division
Maximum variation in sensitivity figure
Minimum overall accuracy of measurement
50 kg
100 mg
20 per cent
100 mg in 10 kg
5 kg
10 mg
20 per cent
10 mg in 500 g
200 g
1 mg
20 per cent
1 mg in 100 g
50 g
0.4 mg
20 per cent
0.4 mg in 5 g
2 g
0.05 mg
20 per cent
0.05 mg in 1 mg

2.1 The standard deviation of ten consecutive rest points for every working standard balance shall not be more than one scale division.

2.2 The deviation in arm ratio from unity, for every working standard equi-arm balance shall not be more than the fraction equal to sensitivity figure divided by the full load (both being taken in the same unit)

3. Every working standard digital type balance shall conform, as regards value of verification scale interval as given below :—

Capacity
Max. value of verification scale interval

Type of weights to be verified

50 kg
1 g

Non-bullion : 50 kg and 20 kg

20 kg
0.1 g

Bullion : 10 kg, 5 kg;
Non-bullion : 20 kg to 2 kg

2 kg
10 mg
Bullion : 2 kg to 500 g;
Non-bullion : 2 kg to 200 g
200 g
0.1 mg
Bullion : 200 g and below;
Non-bullion : 200 g and below

4. The standard deviation of the 10 consecutive rest points for every working standard balance shall not be more than one scale division.

5. The deviation in arm ratio from unity, for every working standard equi-arm balance shall not be more than a fraction equal to sensitivity figure divided by full load, (both being taken in the same unit).

6. The variation in time periods at different load for every working standard balance shall not be more than 20 per cent.

7. Every indoor type working standard balance shall be provided with a device so that the contact between the knife-edges and their respective planes is broken when the balance is in arrested position.

Note: For verification of bullion or carat weights, only indoor type working standard balances shall be used.

FIFTH SCHEDULE
[See Rule 11 ]
PART I
Weights (Other than Carat Weights)

General

This Part deals with the following categories of weights:—

(A) Iron weights, parallelopiped, (50 kg to 5 kg)

(B) Cylindrical knob type weights (10 kg to 50g)

(C) Iron weights, hexagonal (50 kg to 50 g)

(D) Bullion weights (10 kg to 1 g) and

(E) Sheet metal weights (500 mg to 1 mg)

A.—IRON WEIGHTS PARALLELOPIPED (50 kg to 5 kg)

1. Denominations

Parallelopiped iron weights shall have the following denominations:—

Kilogram series : 50, 20, 10 and 5.

2. Shape

(a) The weights shall be integral and in the form of parallelopiped rectangles with corners rounded off and having a rigid handle for ease of handling.

(b) The shapes shall be as shown either in Fig. 3 or in Fig. 4.

3. Material

(a) Body : The body shall be made or manufactured from grey cast iron.

(b) Handles : Handles shall be made or manufactured from the following materials :

(i) Type 1 weights—Steel tube without soldering

(ii) Type 2 weights—Cast along with the body

(c) Method of manufacture:

The weights shall be made or manufactured by means of any suitable foundry and moulding process.

4. Loading holes

(a) The weights shall be provided with loading holes of either Type 1 or Type 2 indicated below:

Type 1 loading hole

(i) The loading hole shall be located within the tube which forms the handle (See Fig. 3).

(ii) The loading hole shall be closed either with a screwed brass plug or a brass disc. The screwed brass plug shall be provided with a screw driver slot and the brass disc shall have a central hole to facilitate lifting.

(iii) The plug or a disc shall be sealed by means of a lead pellet pressed firmly into an internal circular slot or in the threaded part of the tube.

Type 2 loading hole

(i) The loading hole shall be cast in one of the upper surfaces of the weights and shall open out on the upper surface (See Fig. 4).

(ii) This loading hole shall be closed by a plate cut from mild steel.

(iii) The mild steel plate shall be closed by a lead pellet pressed firmly into the conical hole.

(b) In case of new weights, about two-third of the depth of the loading hole shall remain empty after adjustment.

5. Markings

(a) The denomination of the weight and the marker's or manufacturer's name or trade mark shall be indicated indelibly in the sunken form or in relief, on the upper surface of the central portion of the weight. (See Fig. 3 and Fig. 4.)

(b) The denomination of the weight shall be indicated in the international form of Indian numerals in an indelible manner with the symbols as illustrated below :

……….. or……… 5 kg.

Note : The abbreviation ……. or ……… may be indicated in the regional script.

6. Dimensions

(a) The dimensions of the two types of weight shall be as specified in Tables 1 and 2.

(b) The tolerances on dimensions shall be + 5 per cent.

TABLE 1
Parallelopiped Weights Dimensions for Type 1 Weights

( In millimetres )

Denomination
A
A‘
B
B‘
H
C
D
E
F

G/G'

5 kg
150
152
75
77
84
36
30
6
66
12/20
10 kg
190
193
95
97
109
46
38
8
84
12/20
20 kg
230
234
115
117
139
61
52
12
109
24/32
50 kg
310
314
155
157
192
83
74
16
152
24/32

 

  Denomination
I
J
K
T
L
N
O
U
V
W
P
5 kg
145
5
12
M16 x 1.5
14
1
2
16.5
18
16
5
10 kg
185
6
16
M16 x 1.5
14
1
2
16.5
18
16
5
20 kg
220
8
20
M27 x 1.5
21
2
3
27.5
30
27
8
50 kg
300
10
25
M27 x 1.5
21
2
3
27.5
30
27
8

Sides A and A‘ as also B and B‘ may be inversed.

TABLE 2
Parallelopiped Weights Dimensions for Type 2 Weights

( In millimetres )

Denomination
A
A'
B
B'
H
C
D
E
F
G
J
K
M
N
P
5 kg
150
152
75
77
84
36
30
6
66
19
5
12
16
13
55
10 kg
190
193
95
97
109
46
38
8
84
25
6
16
35
25
70
20 kg
230
234
115
117
139
61
52
12
109
29
8
20
50
30
95
50 kg
310
314
155
157
192
83
74
16
152
40
10
25
70
40
148

Sides A and A' also B and B' may be inversed.

7. Finish

The weights shall be finished smooth and be free from dross, pits, blow-holes and other defects. They shall be protected against corrosion by applying an appropriate coating which is resistant to normal usage and wear and tear.

8. Permissible error

The maximum permissible errors shall be as specified below :

Denomination
Permissible error
Verification (mg)

Inspection (mg)

50 kg
7500
± 7500
20 kg
3000
± 3000
10 kg
1500
± 1500
5 kg
750
± 750

9. Stamping

The Legal Metrology Officer's seals shall be stamped on the lead pellet within the loading hole. (See Fig. 3 & Fig. 4).

B.—CYLINDRICAL KNOB TYPE WEIGHTS (10 kg. to 1 g)

1. Denominations

Cylindrical weights shall have the following denominations :

Gram series : 500, 200, 100, 50, 20, 10, 5, 2 and 1

Kilogram series : 10, 5, 2 and 1

2. Shape

(a) The weights shall be integral and cylindrical in shape and provided with a flattened knob for ease of handling.

(b) The shapes shall be as shown in Fig. (5).

3. Material

The weights shall be made or manufactured from brass, gun metal or bronze; grey cast iron may also be used for weights from 10 kg to 200 g but grey cast iron weights shall not be used for weighment of gold, silver, precious metals or their products.

4. Method of manufacture

The weights shall be made or manufactured by any suitable method as may be applicable to the selected material.

5. Loading hole

(a) Weights of denominations 10 g to 1 g both inclusive, shall be solid, integral weights without a loading hole.

(b) Weights of denominations 10 kg. to 20 g both inclusive, shall be provided with a loading hole.

(c) The loading hole shall be cylindrical and shall pass through the axis of the weight open out on the upper surface of the knob and have wider diameter at its upper end as shown in Fig. 5.

(d) The loading hole shall be closed either by means of a threaded brass plug or a flat brass disc. (See Fig. 5)

Note : The thread used shall be that commonly known as ‘ISO Metric'.

(i) The threaded plug shall have a slot for adjusting it by means of a screw driver.

(ii) The flat disc shall be provided with a suitable hole in the centre to facilitate handling.

(e) The plug or the flat disc shall be closed by means a lead pellet pressed firmly into the circular groove in the wider part of the loading hole.

(f) Weights without a loading hole shall be adjusted by machining or grinding.

(g) Weights with loading hole shall be adjusted with heavy metallic materials such as lead shots.

(h) In the case of new weights about two-thirds of the depth of the loading hole shall remain empty after adjustment.

6. Marking

(a) The denomination of the weight and the maker's or manufacturer's name or trade mark shall be indicated indelibly, in the sunken form or in relief, on the flat knob. (See Fig. 5)

(b) The denomination of weights of 10 kilograms to 500 grams may also be indicated on the cylindrical body of the weight, provided that the numerals and letters of the symbol shall be larger than those used for indicating them on the knob.

(c) The denomination of the weight shall be indicated in the international form of Indian numerals in an indelible manner with the symbols as illustrated below :

………. or ………… 5 kg

  ……….. or …………..   100 g

Note : The abbreviation ……….. or …………… or …………. may be indicated in the regional script.

7. Dimensions

(a) The dimensions of cylindrical weights shall be as specified in Tables 3 and 4.

(b) The tolerances on dimensions shall be :

(i) for weights 1 kg. and below + 10 per cent

(ii) for weights above 1 kg + 5 per cent.

TABLE 3
Cylindrical Knob Type Weights—Dimension for Weights in mm

Denomination
U
V
W
H
Y
R
J
K
10 kg
100
90
58
According to material
17
15
3
10
Without loading
hole
5 kg
80
72
46
13
12
2
10
2 kg
60
54
36
10
9
2
5
1 kg
48
43
27
8
7
2
5
500 g
38
34
22
6
5.5
1.5
3.2
200 g
28
25
16
4.5
4
1.5
3.2
100 g
22
20
13
4
3.5
1
2
50 g
18
16
10
3
2.5
1
2
20 g
13
11.5
7.5
2
1.8
0.5
1.5
10 g
10
9
6
1.6
1.5
0.5
1
5 g
8
7
4.5
1.4
1.25
0.5
1
2 g
6
5.5
3
1
0.9
0.5
1
1 g
6
5.5
3
1
0.9
0.5
1

TABLE 4
Cylindrical Knob Type Weights—Dimension for Loading Hole Variety I and II in mm.

Denomination
A
B
C
D
E
F
G
L
T
I
M
N
P
S
20 g
3
18
5.5
2.5
6.5
1.5
1
9
M4 x 0.5
5
1
5
5
1
50 g
4.5
25
7.5
3.5
9
2
1
10
M6 x 0.5
5
1.5
7
7

1.5

100 g
4.5
30
7.5
3.5
9
2
1
10
M6 x 0.5
5
1.5
7
7
1.5
200 g
7
40
10.5
4.5
12
2.5
1.5
15
M8 x 1
8
2
10
10
2
500 g
7
50
10.5
4.5
12
2.5
1.5
15
M8 x 1
8
2
10
10
2
1 kg
12
65
18.5
7
20
4
2.5
20
M14 x 1.5
13
3
18
18
3
2 kg
12
80
18.5
7
20
4
2.5
20
M14 x 1.5
13
3
18
18
3
5 kg
18
120
24.5
8
26.5
4
2.5
35
M20 x 1.5
18
4
24
24
3
10 kg
18
160
24.5
8
26.5
4
2.5
35
M20 x 1.5
18
4
24
24
3

8. Finish

The weights shall be polished smooth. They may be protected against corrosion by applying an appropriate coating which is resistant to normal usage and wear and tear.

9. Permissible error

The maximum permissible errors shall be as specified below :

Denomination
                                Permissible error
Verification (mg)

Inspection (mg)

10 kg
1500
±1500
5 kg
750
±75
2 kg
300
±300
1 kg
150
±150
500 g
75
±75
200 g
30
±30
100 g
15
±15
50 g
10
±10
20 g
8
±8
10 g
6
±6
5 g
5
±5
2 g
4
±4
1 g
3
±3

10. Stamping

(a) The Legal Metrology Officer's seals shall be stamped on the load pellet within the loading hole, where loading hole is provided.

(b) The Legal Metrology Officer's seals shall be stamped on the bottom of weights which have no loading hole.

C.—IRON WEIGHTS, HEXAGONAL (50kg to 50g)

1. Denominations

Hexagonal iron weights shall have the following denominations :
Gram series : 500, 200, 100 and 50.
Kilogram series : 50, 20, 10, 5, 2 and 1.

2. Shape

(a) The weights shall be integral and hexagonal. The shape shall be as shown in Figures 6 and 6A.

(b) The weights of denominations of 50 kg and down to and including 5 kg shall be provided with cast-in handles made of mild steel.

(c) The weights of denominations 2 kg and down to and including 50 g shall nest with each other.

3. Material

The weights shall be made or manufactured from grey cast iron.

4. Method of manufacture

The weights shall be made or manufactured by means of any suitable foundry and moulding process.

5. Loading hole

The weights must have a loading hole formed at the foundry

(a) For weights in Figure 6 this hole must be in the shape of a right circular cone located axially and opening into the bottom face of the weight with its smaller diameter.

(b) For weights in Figure 6A this hole must be in the shape of a frustum of a pyramid with rectangular base and opening into the bottom face of the weight with its smaller end.

(c) In the case of new weights about two-thirds of the depth of the loading hole shall remain empty after adjustment.

6. Marking

(a) The denomination of the weights and the maker's or manufacturer's name or trade mark shall be indicated indelibly in the sunken form or in relief, on the upper surface of the central portion of the weight (See Fig. 6).

(b) The denomination of the weight shall be indicated in the international form of Indian numerals in indelible manner with the symbols as illustrated below (See Fig. 6).

………….. or …………… 2 kg

  …………… or ……….  200 g

Note : The abbreviation …………. or …………..may be indicated in the regional script.

7. Dimensions

(a) The dimensions shall be as specified in Tables 5 and 5A.

(b) The tolerances on dimensions shall be :

(i) for weights 1 kg and below + 10 per cent

(ii) For weights above 1 kg + 5 per cent.

TABLE 5
Dimensions for Cast Iron or Forged Mild Steel S Weights
(All dimensions in millimetres)

Denomination
A
B
C
D
H
P
Q
R
S
T
2 kg
94
101
78
41
10
34
30
9
18
4
1 kg
73
79
62
34
8
32
28
8
16
4
500 g
57
62
47
27
6
23
20
6
13
3
200 g
42
48
38
21
6
22
20
4
9
3
100 g
33
38
31
17
5
18
16
3
7
2.5
50 g
27
31
24
12
3
16
14
3
5
2

TABLE 5A
Dimensions of Cast Iron Weights with Cast-in Handles

Denomination
A
B
C
D
E
G
P
Q
R
S
T
50 kg
236
253
134
170
100
27
58
48
24
102
32
20 kg
188
200
112
113
90
21
44
38
19
66
22
10 kg
152
161
92
88
74
18
36
30
15
54
19
5 kg
125
132
75
65
62
15
29
25
12
40
16

(Dimensions in mm)

8. Finish

The weight shall be finished smooth and be free from pits, blow-holes and other defects. They shall be protected against corrosion by applying an appropriate coating which is resistant to normal usage of wear and tear.

9. Permissible error
The maximum permissible errors shall be as specified below :

Denomination
Permissible error
Verification (mg)
Inspection (mg)
50 kg
7500
±7500
20 kg
3000
±3000
10 kg
1500
±1500
5 kg
750
±750
2 kg
300
±300
1 kg
150
±150
500 g
75
75
200 g
30
±30
100 g
15
±15
50 g
10
±10

10. Stamping

The Legal Metrology Officer's seals shall be stamped on the lead pellet within the loading hole (See Fig. 6).

D.—BULLION WEIGHTS (10 kg to 1 g)

1. Denominations

Bullion weights shall have the following denominations :
Gram series : 500, 200, 100, 50, 20, 10, 5, 2 and 1.
Kilogram series : 10, 5, 2 and 1.

2. Shape

Bullion weights shall be of the following two types :

(i) Cylindrical knob types—Cylindrical knob type weights of denomination 10 kg to 1 g, both inclusive, shall be of the shape as specified in paragraph B-2 of this Part (See also Fig. 5) but shall bear indications, specified in paragraph 6 to indicate that they are bullion weights.

(ii) Flat cylindrical type—Flat cylindrical type weights of denominations 1 kg to 1 g both inclusive, shall be flat cylindrical in shape, without a knob and shall nest with each other (See Fig. 7).

3. Material

Weights shall be made or manufactured from brass, gun metal, bronze or the like.

4. Method of manufacture

Weights shall be either cast, pressed or turned from rods, or made or manufactured by any other suitable method as may be applicable to the selected material.

5. Loading holes

(a) Weights of denominations 10 kg to 20 g, both inclusive, made or manufactured according to requirements specified in paragraph 11 of this Part, shall have loading holes of the type specified for them.

(b) Weights of denominations 10 g to 1 g, both inclusive of either type shall be solid integral weights without a loading hole.

(c) Flat cylindrical weights from 1 kg to 20 g both inclusive, shall have loading holes, in the shape of a right circular frustum of a cone located axially and opening into the bottom face of the weight with its smaller diameter
(See fig. 7).

(d) In the case of new weights about two-thirds of the depth of the loading hole shall remain empty after adjustment.

6. Markings

(a) The denominations and other marking on cylindrical knob type weights shall be as specified in paragraph 15 of this Part.

(b) Cylindrical knob type weights of denomination 100g to 1g, both inclusive, shall be marked on the body with a ‘diamond' and those of denominations 10 kg to 200g, both inclusive, shall be marked on the knob with the words ‘Bullion' and ‘ (cqfy;u) within a ‘diamond'.

(c) The denominations of flat cylindrical weights and the maker's or manufacturer's name or trade mark shall be indicated indelibly, in the sunken form or in relief, on the upper surface of the central portion of the weights (See Fig. 7).

(d) Flat cylindrical weights of denominations 10 g to lg, both inclusive, shall be marked with only a ‘diamond' and those of denominations 1 kg to 20 g, both inclusive, shall be marked with the words ‘Bullion' and (cqfy;u) within a ‘diamond'.

(e) The denomination of the weight shall be indicated in the international form of Indian numerials in an indelible manner with the symbols as illustrated below (See fig. 7):

…………. or …………… 2 kg

 ……………. or ………….. 10 g

Note: The abbreviation, …………or ………….or ……………. may be indicated in the regional script.

7. Dimensions

(a) The dimensions of cylindrical knob type weights shall be as specified in Tables 3 and 4.

(b) The dimensions of flat cylindrical weight shall be as specified in Table 6.

(c) The tolerances on dimensions for both types of weights shall be—

(i) for weights 1 kg and below + 10 per cent.

(ii) for weights above 1 kg + 5 per cent.

TABLE 6
DIMENSIONS FOR FLAT CYLINDRICAL BULLION WEIGHTS
( All dimensions in millimetres )

Denomination
A
B
C
D
E
F
G
1 kg
80
61.5
20
23
4.0
12
26.6
500 g
61
48.5
16
19
2.5
10
22.5
200 g
48
37.5
14
16
2.0
7
14.8
100 g
37
28.5
12
14
2.0
6
12.7
50 g
28
21.5
10
11
1.5
3
11.0
20 g
21
16.5
9
10
1.5
3
8.4
10 g
16
12.5
**
**
1.5
**
6.9
5 g
12
9.5
**
**
1.0
**
5.9
2 g
9
7.0
**
**
1.0
**
4.4
1 g
6.5
**
**
**
**
**
3.6

8. Finish

The surface of the weights shall be polished, smooth and shall not show any porosity to the naked eye.

9. Permissible error

The maximum permissible errors shall be as specified below :

Denomination
Permissible error
Verification (mg)
Inspection (mg)
10 kg
500
±500
5 kg
250
±250
2 kg
100
±100
1 kg
50
±50
500 g
25
±25
200 g
10
±10
100 g
5
±5
50 g
3
±3
20 g
2.5
±2.5
10 g
2.0
±2.0
5 g
1.5
±1.5
2 g
1.2
±1.2
1 g
1.0
±1.0

10. Stamping

(a) The Legal Metrology Officer's seals shall be stamped on the lead pellet within the loading hole, where loading hole is provided.

(b) The Legal Metrology Officer's seals shall be stamped on the bottom of weights which have no loading hole.

E.—SHEET METAL WEIGHTS

1. Denominations

Sheet metal weights shall have the following denominations:—
Milligram series : 500, 200, 100, 50, 20, 10, 5, 2 and 1.

2. Shape

(a) Bullion weights shall be circular in shape and shall have one edge bent for ease of handling (See Fig. 8).

(b) Non-bullion weights shall have the following shapes and shall have one edge bent for ease of handling (See Fig. 9).

Denomination (mg)
Shape after bending along one of the sides
550500
Regular hexagon
220200
Square
110110
Equilateral triangle

3. Material

Sheet metal weights shall be made or manufactured from brass, stainless steel, aluminium nickel-silver or cupro-nickel sheets.

4. Method of manufacture

Sheet metal weights shall be made or manufacture by pressing or by any other suitable process.

5. Markings

(a) Sheet metal weights shall bear only the denomination and symbol for ‘milligram' as indicated below (See also Fig. 8 and Fig. 9).
(……….) 500 mg

Note : The abbreviation …………. may be indicated in the regional script.

(b) The maker's or manufacture's name or trade mark shall be indicated indelibly on the box containing the sheet metal weights.

(c) The box shall also bear a serial number to identify it.

TABLE 7
DIMENSIONS FOR SHEET METAL WEIGHTS
(NON BULLION) (Fig. 9) (All dimensions in millimetres)

Denomination (mg)
A1
A2
A3
B
H
50
14.0
-
-
2.0
3.0
200
...
12.0
...
2.0
3.0
100
...
...
12.0
2.0
2.5
50
8.0
...
...
1.5
2.5
20
...
7.0
...
1.5
2.5
10
...
...
7.0
1.5
2.5
5
4.5
...
...
1.0
2.0
...
4.0
...
1.0
2.0
...
...
4.0
1.0
2.0

6. Dimensions

(a) The dimensions of sheet metal weights shall be as specified in Tables 7 and 8.

(b) The tolerances on dimensions shall be + 10 per cent.

TABLE 8
DIMENSIONS FOR SHEET METAL WEIGHTS
(BULLION) (Fig. 8)
( All dimensions in millimetres )

Denomination
D
C
H
500 mg
15
2.0
3.0
200 mg
13
2.0
3.0
100 mg
11
2.0
2.5
50 mg
9
1.5
2.5
20 mg
8
1.5
2.5
10 mg
7
1.5
2.5
5 mg
6
1.0
2.0
2 mg
5
1.0
2.0
1 mg
4
1.0
2.0

7. Finish

The sheet metal weights shall be clearly sheared and free from burrs. The stamped markings on sheet metal weights shall be legible and deep enough to ensure indelibility but not so deep as to crack the sheet metal weights.

8. Permissible error

The maximum permissible errors shall be as specified below :

Denomination (mg)
Maximum permissible error
Verification
Inspection
Bullion (mg)
Non-bullion (mg)
Bullion (mg)

Non-bullion (mg)

1
2
3
4
5
500
0.8
2.5
±0.8
±2.5
200
0.6
2.0
±0.6
±2.0
100
0.5
1.5
±0.5
±1.5
50
0.4
1.2
±0.4
±1.2
20
0.3
1.0
±0.3
±1.0
10
0.25
0.8
±0.25
±0.8
5
0.20
0.6
±0.20
±0.6
2
0.20
0.6
±0.20
±0.6
1
0.20
0.6
±0.20
±0.6

9. Stamping

(a) Legal Metrology Officer's seals shall not be affixed on weights of 10 mg, 5 mg, 2 mg and 1 mg. These weights shall be authenticated by the issue of a certificate of verification which shall also mention the serial number on the box containing the weights.

(b) Legal Metrology Officer's seal for year alone shall be stamped on sheet metal weights of 20 mg.

(c) The Legal Metrology Officer's seals (namely, year, quarter and identification) shall be stamped on sheet metal weights of denominations 500 mg to 50 mg, both inclusive.

PART II—CARAT WEIGHTS

1. General

This Part deals with the requirements for carat weights intended for use in weighing pearls, diamonds and other precious stones.

2. Denominations

The denominations of carat weights shall be as given below (the gram and milligram equivalents are shown against each for ready reference) :

(a) KNOB WEIGHTS
(b) SHEET METAL WEIGHTS
Denomination carat
Equivalent g
Denomination carat
Equivalent mg
500
100
2
400
200
40
1
200
100
20
0.5
100
50
10
0.2
40
20
4
0.1
20
10
2
0.05
10
5
1
0.02
4
0.01
2
0.005
1

3. Knob weights

(a) Materials

(i) The weights shall be made from rolled, drawn or extruded material and shall not be cast.

(ii) The weights shall be made from brass, bronze, gun-metal, nickel-chromium alloy or non-magnetic stainless steel.

(b) Shape and dimensions

The shape and dimensions of the weights shall be as shown in Fig. 10 and
Table 9.

(c) Permissible error

The maximum permissible errors shall be as specified below :

Denomination
Verification
Inspection
Carat
mg
mg
500
5.0
±5.0
200
3.0
±3.0
100
2.5
±2.5
50
2.0
±2.0
20
1.5
±1.5
10
1.2
±1.2
5
1.0
±1.0

TABLE 9
NOMINAL DIMENSIONS OF KNOB CARAT WEIGHTS
[ Clause 3(b) ]
All dimensions in millimetres

Denominations Carat
A*
C**
D
E
F
G
H
500
12.0
0.4
4.0
10.0
6.0
32.0
14.2
200
10.0
0.4
3.0
8.5
5.0
23.0
10.8
100
8.0
0.4
2.5
7.0
4.0
19.0
7.9
50
6.0
0.3
2.0
5.5
3.0
15.0
6.4
20
5.0
0.3
2.0
4.0
2.0
11.0
4.6
10
4.0
0.3
1.5
3.0
1.5
9.0
3.5
5
3.0
0.2
1.5
2.5
1.5
7.0
2.9

* The cross-section of the top of the knob is elliptical for all weights major axis being twice the minor axis (therefore for all weights B= A/4)

** This is a recommended dimension.

Note : With a material of density 8400 kg/m 3 (exactly) the above dimensions will give weights which possess masses to within the required tolerance limits on the plus side (this ensures a longer life for the weights). However, as the density of the material may vary considerably as also the manufacturing techniques, a tolerance of + 10 per cent is allowed on all obligatory dimensions (that is those other than C). Final values of masses can be adjusted by controlling the dimension H.

4. Sheet metal weights

(a) Materials— Weights of denominations 0.2 carat and below shall be made of aluminium sheet. Weights of higher denominations shall be made of sheets of brass, aluminium, nickel-silver, nickel chromium alloy, bronze or cupro-nickel.

(b) Shape and dimensions­— Sheet metal weights shall be square with one edge bent for ease of handling. (Fig. 11). They shall have dimensions given in Table 10.

(c) Permissible error

The maximum permissible errors shall be as specified below:—

Denomination
Verification
Inspection
Carat
mg
mg
1
2
3
2
0.8
±0.8
1
0.6
±0.6
0.5
0.5
±0.5
0.2
0.4
±0.4
0.1
0.3
±0.3
0.05
0.25
±0.25
0.02
0.20
±0.20
0.01
0.20
±0.20
0.005
0.20
±0.20

TABLE 10
Nominal dimension for sheet metal carat weights

Denomination
Size
Carat
mm
2
12
1
10
0.5
9
0.2
8
0.1
7
0.05
6
0.02
5
0.01
4
0.005
3

Tolerance + 10 per cent

5. Manufacture and finish

(a) The surface of the weights shall be reasonably smooth. Sheet metal weights shall be smoothly sheared and shall be free from burrs.

(b) For better stability and finish, the weights may be nickel, or rhodium plated.

6. Marking

(a) Every weight, except weights of 50 carat and lower denominations, shall have the manufacturer's name or trade mark and the denomination indelibly marked on it.

(b) The denomination shall consist of the International form of Indian numeral prefixed and suffixed by the letter ‘…..' and ‘c' respectively except that in the case of weights below 50 carat, only the numerals shall be marked. The size of numerals and letters indicating the denomination of weights shall be at least twice the size of letters indicating the manufacturer's name or trademark.

Note : The abbreviation ‘……..' may be indicated in the regional script.

(c) The marking shall be legible and deep enough to ensure indelibility over a long period of use, but not so deep as to crack the weight itself.

7. Packing

(a) Each set of carat weights shall, in addition to the series of denomination specified under 2, consist of an additional piece of weight of 2 carat and the relevant decimal multiple of two.

(b) The weights shall be supplied in a suitable velvet-lined box. The small sheet metal weights shall be so housed and provided with a cover of glass or any other transparent material that they will not get dislodged from their proper places. The box shall also contain a pair of forceps for lifting the weights.

PART III—STANDARD WEIGHTS FOR TESTING OF HIGH CAPACITY WEIGHING MACHINES

1. Scope

These specifications shall apply to standard weights having a nominal value equal to or greater than 50 kg, used for testing (and adjusting, where appropriate) of high capacity weighing machines in accuracy class III (medium) and class IIII (ordinary), defined in the Metrological regulations for non-automatic weighing machines.

(a) It sets forth the technical and metrological requirements to which these standard weights must conform. In particular it establishes the values of the maximum permissible errors for standard weights and minimum densities as functions of the maximum number of scale divisions on the machines to be verified using these weights.

2. Nominal values

The nominal value of the standard weight is 50 kg, or of the form k x 10 n kg, where k is generally equal to 1, 2 or 5, and n is whole number equal to or greater than 2.

3. Shape

The standard weights must have a relatively simple shape, with no sharp edges or corners. They shall not have any cavities liable to cause a rapid accumulation of dirt. If they are intended to run on a flat surface (or on rails), they must be equipped with roller tracks (or grooves) of limited area.

4. Basis of adjustment

The standard weights must be adjusted taking the reference conditions applicable to the adjustment of standard weights as follows:

(a) standard reference density : 8000 kg/m 3 ,

(b) ambient air density : 1.2 kg/m 3 , and

(c) equilibrium in air at 20 o C, without correction for air buoyancy.

5. Adjusting cavity

The standard weights must include one or more adjusting cavities. It must be possible to seal the closure of these cavities; the closures must be water-tight and airtight (e.g. by means of a joint). The volume of adjusting cavities must be at least equal to 5/100 of the volume of the standard weight. Furthermore, it is desirable that, after the initial adjustment, a volume of at least 1/100 of the volume of the standard weight remains empty.

6. Material

Standard weights are in general made of grey cast iron. They may be made of one or more other materials, provided the provisions of paragraph 8 are observed. The material used must be of such hardness and strength that they withstand the loads and shocks liable to occur under normal conditions of use.

7. Surface condition

The standard weights may be coated with materials suitable for providing protection against corrosion by rendering their surface impermeable. This coating must withstand shocks and atmospheric conditions. Zinc-plating is an example of a coating which meets with these specifications.

8. Metrological characteristics

The maximum permissible error for the standard weights must not exceed 1/3 of the maximum permissible error for the corresponding load considered, on the weighing machine under verification. The absolute error for various denominations of standard weights shall be as given in Annexure I. These maximum permissible errors for the standard weights must therefore be compatible with the number of scale divisions on the machines which they are intend to verify. Furthermore, the density of standard weights must be such that a variation of + 10 per cent ambient air density, with respect to its reference value, does not produce a variation, in the result of weighing the standard weight in air, exceeding 1/4 of its maximum permissible error. By way of application of these requirements, the following table gives examples of the relation amongst:—

(a) the maximum number of scale divisions “n” on weighing machines under verification (assumed to be in accuracy class III);

(b) the maximum permissible positive or negative relative error on standard weights used for initial verification of these machines; and

(c) the corresponding lower limit for the density of the standard weights.

TABLE

Maximum number of scale divisions “n” on weighing machines (accuracy class III), capable of verification with the standard weights during verification
Maximum permissible positive or negative relative error on the standard weights
Minimum density kg/m 3
(1)
(2)
(3)
1000
3.3/10000
1231
3000
1.7/10000
2087
5000
1.0/10000

3000

10000
0.5/10000
4364

Note: Independent of the requirements concerning the density of the weights, it is desirable to obtain—particularly for reference standards or those of a high nominal value—a density of about 8000 kg/m 3 . For example, a cast iron body may be used, which incorporates a special cavity in which a lead core may be cast, with a mass of approximately 30 percent of the total nominal mass of the standard.

9. Inscriptions and markings

Standard weights must carry their nominal value in numerals, followed by the symbol for the unit used and a verification mark.

10. Adjustment and verification

Adjustment of the standard weights must be such as to comply with the maximum permissible errors given in this specification. In particular this may be achieved in the case of adjustment by the double substitution weighing technique (Gauss transposition method, or Borda substitution method), using as reference standards, weights having an error of less than 1/3 of the maximum permissible error for the weight to be adjusted, and as the comparator machine, a weighing machine for which the limit of repeatability error does not exceed 0.2 times of the maximum permissible error for the weight to be adjusted.

Note: Standard weights used for verification of a weighing machine with “n” scale divisions may be used for the re-verification of a weighing machine with “pn” scale divisions, where the maximum permissible error for this re-verification is “p” times (where p has a value equal to or greater than 1), the maximum permissible error on verification.

11. Dimensions

The Dimensions for 500 kg and 1000 kg denominations weights shall be as given in Annexure II.

ANNEXURE I
ABSOLUTE ERRORS FOR STANDARD WEIGHTS

Normal Value kg
Maximum permissible error for the standard weights
3.3/10,000
1.7/10000
1/10000

0.5/10000

Corresponding absolute error (grams)
50
17
8.5
5
2.5
100
33
17
10
5
200
66
33
20
10
500
170
85
50
25
1000
330
170
100
50
2000
660
330
200
100
5000
1700
850
500
250
1000
3000
5000
10000

Maximum number of scale divisions < n > on weighing machines (accuracy class III) capable of being verified (verification) with the standard weights (see note given at clause 10)

ANNEXURE II
TYPICAL EXAMPLES

This annexure contains diagrams of weights used for testing of high capacity weighing machines, which are considered suitable for use as patterns because of their design and ease of use.

RECTANGULAR STANDARD WEIGHTS
500 kg and 1000 kg
SUITABLE FOR STACKING
Dimensions (mm)

a
b
c
500 kg
273
100
100
1000 kg
504
120
140

RECTANGULAR STANDARD WEIGHT 1000 KG
SUITABLE FOR STACKING

 

CYLINDRICAL STANDARD WEIGHTS
500 kg and 1000 kg
SUITABLE FOR STACKING AND ROLLING
Dimension (mm) FOR 500 kg WEIGHT

 

r = 10
R = 20

 

SIXTH SCHEDULE
SPECIFICATIONS FOR MEASURES
[ Rule 12 ]
PART I
LIQUID CAPACITY MEASURES

1. General

This Part deals with two types of cylindrical liquid measures, namely the dipping and the pouring types, and one type of conical measures.

2. Denominations

The denominations of the different types of measures shall be as under :

Cylindrical measures

Conical measures

Dipping type
Pouring type
1 litre
2 litres
20 litres
500 ml
1 litre
10 litres
200 ml
500 ml
5 litres
100 ml
200 ml
2 litres
50 ml
100 ml
1 litre
20 ml
50 ml
500 ml
20 ml

200 ml

100 ml

3. Shapes and dimensions

(a) The shape and dimensions of cylindrical measures (dipping and pouring types) shall be as shown in Figs. 12 and 13 and Table 11.

TABLE 11
Nominal dimensions of cylindrical capacity measures

Denominations
D
H
B
G
2 litres
120
180
360
250
1.60
1 litre
95
142
254
210
1.60
500 ml
75
114
224
160
1.60
200 ml
55
83
166
120
1.25
100 ml
44
66
132
100
1.25
50 ml
35
52
104
80
1.25
20 ml
26
38
76
60
1.00

Note: 1. All dimensions in millimetres.

    2. Tolerance on dimensions + 10 per cent.

TABLE 12
NOMINAL DIMENSIONS OF CONICAL CAPACITY MEASURES

Denomination
A
B
C
D
E
F
G Min.
H
J
K
M
20 litres
97
388
388
208
194
390
1.00
35
86
29
30
10 litres
77
308
307
174
154
309
1.00
30
75
26
25
5 litres
61
244
245
147
122
247
0.80
25
65
24
20
2 litres
45
180
180
118
90
182
0.80
20
56
22
16
1 litre
36
143
143
95
72
145
0.63
20
45
18
16
500 ml
28
114
113
74
56
115
0.63
15
35
14
12
200 ml
21
84
84
53
42
86
0.63
10
24
10
8
100 ml
17
66
67
41
34
69
0.63
10
18
7
8

Note 1 : All dimensions in millimetres.

Note 2 : Tolerance on dimensions + 10 per cent except in case of 10 litre and 20 litre measures for which the tolerance shall be + 5 per cent.

4. Material

(a) Cylindrical measures—The body of cylindrical measures shall be manufactured in one piece from aluminium alloy sheets, brass sheets or stainless steel sheets. The minimum thickness of the sheets shall be as specified in Table 11.

(b) Conical measures—The conical measures shall be fabricated from galvanised steel sheets, aluminium alloy sheets, copper sheets, brass sheets, stainless steel sheets or tinplate. The minimum thickness of the sheets shall be as specified in Table 12.

(c) The handles for the measures shall be fabricated from the same material as that used for the body.

5. Manufacture and finish

(a) Cylindrical measures made of brass sheets and copper sheets shall be tinned or tin-plated uniformly all over the inside as well as the outside surfaces. Conical measures made of brass sheets or copper sheets, shall be well tinned or tin-plated uniformly all over the inside when they are used for measuring commodities like milk, edible oils and such other food articles.

(b) The handles shall be of robust construction and shall be well formed and shaped generally as shown in Figs. 12, 13 and 14. They shall be securely fixed to the body by means of riveting, soldering or brazing.

Note 1: Capacity measures when used for measuring milk shall have the handle fixed by welding, soldering or other suitable methods. Brazing so as not to leave pockets in which dirt may accumulate.

Note 2: Dipping type of cylindrical measures may also have handles substituted by two suitable but diagonally opposite brackets affixed to the walls of the measure by means of soldering, brazing or welding so as to hold the measure properly by a handle at right angles to the walls of the measures to facilitate its use in hot and boiled milk trade.

(c) The measures shall be free from any surface defects and indentations and shall be smoothly finished at the top.

(d) Cylindrical measures shall be provided with a well formed and proportioned spout to facilitate pouring.

(e) Conical measures shall be provided with a retaining lip to avoid spilling. The retaining lip shall be provided with a plug of suitable material with a collar to receive the lead for the Legal Metrology Officer's seal. A small hole, about 5 mm in diameter shall be provided at the bottom of the retaining lip to indicate the level to which the measures shall be filled and the hole shall be located on the side at right angles to the handle. The bottom of conical measures shall be suitably reinforced.

(f) The measures shall be so designed that, when they are tilted 120 degrees from the vertical, they shall become completely empty.

(g) The finished measures shall have adequate robustness for durability.

6. Permissible error

The maximum permissible errors shall be as specified:

MAXIMUM PERMISSIBLE ERRORS (In ml)

................................................................

Denomination Verification in excess only   Inspection  
  Cylindrical measures Conical measures Cylindrical measures Conical measures  
                  In excess only Excess Deficiency Excess

Deficiency

 
20 l ... 100

Same as in verification
...

...

 

... Same as in verification 50
10 l ... 50 ... 25
5 l .. 30 ... 15
2 l 30 15 15 7.5
1 l 20 10 10 5
500 ml 15 8 7.5 4
200 ml 8 4 5 2
100 ml 5 3 2.5 1.5
50 ml 3 ... 1.5 ...
20 ml 2 ... 1 ...

7. Marking

(a) Every cylindrical measure shall have the denomination and manufacturer's name or trade mark indelibly stamped on it. In the case of conical measures, the denomination and manufacturer's name or trade-mark shall be either embossed on the body or indelibly marked on a name plate securely fixed to the body.

(b) The denominations shall be indicated with the abbreviations ‘l' and…….. in Hindi] for litre; and ml and ……….. to indicate millilitre.

Note : The abbreviation …….. or ……….. may be indicated in the regional script.

The size of numerals and letters indicating denominations on the measures shall be twice the size of the letters indicating the manufacturer's name or trade mark.

8. Stamping

(a) Cylindrical capacity measures: The Legal Metrology Officer's seal shall be stamped just above the indication of the denomination of the capacity measure.

(b) Conical capacity measures: The Legal Metrology Officer's seal shall be stamped on the lead pellet provided for this purpose.

PART II
DISPENSING MEASURES

1. General

This Part deals with two types of dispensing measures made of glass or transparent plastic materials, used for dispensing purposes. Conical dispensing measures of capacity 100 ml may also be used in the sale of liquor.

2. Types and denominations

Dispensing measures shall be of the following types and denominations:—

(a) Conical measures —200 ml, 100 ml, 50 ml, 20 ml, 10 ml and 5 ml.

(b) Beaker measures —1000 ml and 500 ml.

3. Materials

(a) Glass measures —The measures shall be made from clear and transparent glass. They shall be well annealed; free from stones, cracks and chippings; and as free as possible from blisters and other defects. Lead glass shall not be used for the measures.

(b) Transparent plastic measures —The measures shall be made from a clear and transparent plastic material, manufactured from plasticised polyvinyl chloride or copolymer, the major constituent of which is polyvinyl chloride. The plastic materials used shall not contain any constituents known to be injurious to health and likely to be extracted by contact with liquids.

4. Definition of capacity

The capacity corresponding to any graduation marks is defined as the volume of water at 27 o C, expressed in millilitres, required to fill the measure to that graduation mark at 27 o C, the observer's eye being level with the front graduation marks and the lowest point of the water meniscus appearing to touch the top edge of that mark.

5. Shape, construction, etc. of conical measures

(a) Shape —The measures shall be conical as shown in Figs. 15A to 15G. The 50 ml measures shall be either tall or squat as shown in Figs. 15C and 15D respectively.

(b) Construction

(i) Each measure shall have a pouring lip. The form of the lip shall be such that, when the measure is filled with water to the highest graduation mark, the contents may be poured from the lip in a stream falling clear of the outside of the measure.

(ii) Each measure shall have a base on which it shall stand vertically without rocking when placed on a horizontal surface. The size of the base shall be such that the measure, when empty, shall not fall when placed on a plane inclined at 15 o to the horizontal. The bottom of the measuring space shall be uniformly rounded and shall merge smoothly into the sides of the measure.

(iii) The wall thickness of the measures shall be sufficient to ensure sturdy construction and shall not show any local departures from uniformity.

(iv) The external surface of the measure shall be a cone having an included angle of not less than 13 o and not more than 14 o .

(v) The overall volume of the measure shall be such that when it is filled with water to the highest graduation mark and a volume of water equal to half its nominal capacity is added to it, there shall be no overflow. But, the addition of a further quantity of water equal to quarter the nominal capacity shall result in water overflowing from the pouring lip.

(c) Graduations—

(i) The conical measures shall be graduated in accordance with Table 13.

(ii) With the pouring dip of measure facing to the right, the front graduation marks shall be placed at right angles to and on the right hand side of a vertical line extending from above to the top graduation mark to near the base of the measure and below the bottom graduation mark.

(iii) The graduation marks shall be marked as shown in Figs. 15A to 15G. The marks shall be engraved or etched and they shall be of a uniform thickness not exceeding 0.3 mm., provided that they may taper slightly towards the ends. The graduation marks shall lie in planes perpendicular to the axis of the measure and shall be horizontal when the measure is standing on a horizontal surface.

(iv) Each graduation number shall be etched or engraved close to the end of the graduation mark to which it relates and in such a manner that it would be bisected by a prolongation of that graduation mark.

(v) The numbered graduation marks shall have the minimum length specified in Col. 7 of Table 13. The unnumbered graduation marks shall be at least two-third the length of the numbered graduation marks and clearly shorter than the numbered marks.

(vi) The height of the lowest graduation mark above the lowest point of the bottom of the measuring space shall be within the limits given in Col. 6 of Table 13.

TABLE 13
DETAILS OF CONICAL MEASURES

Denomination
Graduated at
Numbered at
Back Lines at
Lowest Graduation mark
Height of lowest graduation mark above bottom of measuring space
Minimum length of mark
1
2
3
4
5
6
7
ml
ml
ml
ml
ml
ml
ml
200
50,100,120140,160,180,200
50,100,120140,160,180,200
50,100, 200
50
6.5± 0.5
2.0
100
Every 10 ml from 10 to 100 ml
10, 20, 40, 60, 80, 100
20, 60, 100
10
3.0 ± 0.5
1.75
50(Tall)
Every 10 ml from 10 to 50 ml
10, 30, 50
30, 50
10
4.0 ± 0.5
1.5
50(Squat)
Every 10 ml from 10 to 50 ml
10, 30, 50
30, 50
10
2.0 ± 0.5
1.5
20
Every 5 ml from 5 to 20 ml
5, 10, 20
10, 20
5
2.5+0.5
1.25
10
Every ml from 2 to 10 ml
2, 4, 6, 8, 10
2, 6, 10
2
2.5+0.5
1.0
5
Every ml from 1 to 5 ml
1, 3, 5
3, 5
1
2.5+0.5
0.75

(d) Permissible errors —The maximum permissible errors on verification or on inspection shall be as specified below (in ml) :

Capacity corresponding to graduation mark
Measures expect 50 ml (Squat)
50 ml (Squat) measures
200, 180, 160
±3.0
...
140, 120, 100
±2.0
...
90, 80, 70, 60
±1.5
...
50, 40
±1.0
±1.00
30
±0.8
±1.00
20
±0.6
±0.80
15
±0.5
-
10, 9
±0.4
±0.6
8, 7, 6
±0.3
-
5
±0.25
-
4
±0.20
-
3
±0.16
-
2
±0.12
-
1
±0.08
-

Note : The permissible errors, apart from those of the 50 ml squat measure, apply to graduation marks corresponding to the capacities stated, irrespective of the nominal capacity of the conical measure concerned.

6. Shape construction, etc. of beaker measures

(a) Shape —The measure shall be in the form shown in Figs. 16A and 16B.

(b) Construction—

(i) Each measure shall be provided with a pouring lip. The form of the lip shall be such that, when the measure is filled with water to the highest graduation marks, the contents may be poured from the lip in a stream falling clear of the outside of the measure.

(ii) Each measure shall be provided with a base on which it shall stand vertically without rocking when placed on a horizontal surface. The size of the base shall be such that the measure, when empty, shall not fall when, placed on a plane inclined at 15 o to the horizontal. The bottom of the measuring space shall be uniformly rounded and shall merge smoothly into the sides of the measure.

(iii) The overall volume of the measure shall be such that when the measure is filled with water to the highest graduation mark and a volume of water equal to quarter the denomination volume is added to it, the water shall not overflow.

(c) Graduations—

(i) The graduation marks shall be marked as shown in Figs. 16A and 16B and Table 14. The marks shall be etched or engraved and shall be of a uniform thickness not exceeding 0.3 mm, provided that they may taper slightly towards the ends. The graduation marks shall lie in places perpendicular to the axis of the measures and shall be horizontal when the measure is standing on a horizontal surface.

(ii) Each graduation numbered shall be etched or engraved close to the end of the graduation mark to which it relates and in such a manner that it would be bisected by a prolongation of that graduation mark.

(iii) The distance between the highest and the lowest graduation marks and the height of the lowest graduation mark above the inside of the base of the measure shall be in accordance with Cols. (3) and (4) respectively of Table 14.

(d) Permissible error —The maximum permissible errors on verification or on inspection shall be + 7 ml for 1000 ml measures and + 5 ml for 500 ml measure.

7. Marking

Each measure shall have permanently and legibly engraved or etched its denomination in Indo-Arabic numerals, the abbreviations ‘ml' and ………… being used to indicate millilitres. The manufacturer's name or trade mark shall be marked on the underside of the base of each measure.

Note : The abbrevation ………… may be indicated in regional script.

TABLE 14
GRADUATION AND DIMENSIONS OF BEAKER MEASURES

Denomination
Graduation at
Distance between lowest & highest graduation marks
Height of lowest graduation mark above bottom of measuring surface
Diameter of top
Min. Diameter of bae
Overall height
(1) ml
(2)
(3) cm
(4) cm
(*5) cm
(*6) cm
(7)
1000
200 to 1000 ml , ml at each 100 ml: numbered back lines at 200, 600 and 1000 ml
11 ±1
4±1
12
9
23
500
100 to 500 ml at each 50 ml: numbered at each 100 ml: unnumbered back lines at 100, 300 and 500
9±0.5
3± 0.5
10
8
18

* These are only recommendatory

8. Stamping

The Legal Metrology Officer's seal shall be affixed after each verification just above the uppermost graduation marks.

PART III
LIQUOR MEASURES

1. General

This Part deals with the requirements for liquor measures of two types.

2. Types

Liquor measures shall be of the following two types:—

(i) Hand operated, and

(ii) Automatic.

3. Denominations

The denominations of the types of liquor measures shall be as given below:—
Hand operated : 100 ml, 60 ml and 30 ml.
Automatic : 20 ml.

4. Material

The body of the liquor measures shall be made from glass or brass sheet or stainless steel sheet. The minimum thickness of the sheet for liquor measures shall be 1.2 mm.

5. Shapes and dimensions

The shapes and nominal dimensions of hand operated liquor measures and automatic liquor measures shall be as given in Figs. 17, 18 and 19 respectively.

6. Manufacture

(a) Liquor measures made of brass sheet shall be well tinned or silver-plated uniformly all over the inside as well as the outside surface.

(b) Hand operated liquor measures shall be well formed. Measures of 60 ml and 30 ml capacity may be joined together with a common stem by brazing.

(c) The measures shall be free from any surface defects and indentations and shall be smoothly finished.

(d) Automatic liquor measures shall be capable of delivering 30 ml of liquor when tilted at an angle of 120 from the vertical.

(e) Hand operated liquor measures shall have a knurled edge.

7. Permissible error

The maximum permissible errors shall be as given below:—

Denomination
Permissible error
100 ml
±3 ml
60 ml
±2 ml
30 ml
±1 ml

8. Markings

(a) Every liquor measure shall have the denomination and manufacturer's name or trade mark legibly and indelibly marked on it.

(b) The denomination shall consist of international form of Indian numerals and the abbreviations ‘ml' and ……….. to indicate millilitres. The size of numerals shall be twice the size of the letters indicating the manufacturer's name or trademark.

Note : The abbreviation ………… may be indicated in the regional script.

9. Stamping

Legal Metrology Officer's seal shall be affixed after every verification just below the indication of the denomination mark.

PART IV
LENGTH MEASURES (NON-FLEXIBLE)

1. General

This Part deals with the non-flexible type of length measures made or manufactured from metal or wood.

2. Denominations

The denominations of the length measures shall be as follows :—

Metallic measures
Wooden measures
1 m
2 m
0.5 m
1 m
0.5 m

3. Material, shape, etc. of metallic measures

(a) Material —The measures shall be made from mild steel, brass or stainless steel.

(b) Shape and dimensions —The shape and dimensions of the measures shall be as is shown in Fig. 20.

(c) Graduations —The graduation marks shall be made at every centimetre or at every centimetre for the first ten centimetres and thereafter at every five centimetres. The graduation marks at every ten centimetres shall be numbered. The marks at the centimetre divisions shall extend over half the breadth and those at five centimetre divisions over full breadth of the measures. A cross mark shall be provided at 25 cm in the case of 0.5 m measure and at 25, 50 and 75 cm in the case of 1 m measure (See fig. 20).

The graduations shall be only on one side of the measure.

(d) Permissible error —The error on the length between any two consecutive five centimetre graduation marks shall not exceed + 0.25 mm and further the error from the beginning of the measure to any graduation mark shall not exceed 1.0 mm for 1 metre bar and 0.5 mm for half metre bars provided that the errors on the full length of the measures shall not exceed the following limits :

Denomination
Verification

Inspection

Excess
Deficiency
Excess
Deficiency
1 m
1.0 mm
0.5 mm
1.0 mm
1.0 mm
0.5 m
0.5 m
0.25 mm
0.5 mm
0.5 mm

(e) Provision for stampin g—The measures shall be provided with a copper rivet near each end (see Fig. 20) firmly fixed in a hole, countersunk on both sides, for the Legal Metrology Officer's stamp. An arrow head shall be marked at each end of the measure to provide the points for checking the length.

4. Material, shape, etc. of wooden measures

(a) Materials —The measure shall be made from well seasoned timber of any one of the following species:—

(a) Teak ( Tectona grandis Linn. f )

(b) Roseweed ( Delbergia Latifolia Roxb )

(c) Shisham ( Dalbergia sissoo Roxb )

(d) Haldu ( Adhina cordifolia Hoock. f )

(e) Bijasal ( Pterocarpus marsupium Roxb )

(f) Boxwood ( Biaxux sempervirens )

(g) Beech ( Fagus sylvatica )

(b) Shape and dimensions —The shape and dimensions of the measures shall be as shown in Fig. 21.

(c) Graduations —The graduation marks shall be made at every centimetre for the first ten centimetres and thereafter at every five centimetres. The graduation marks at every ten centimetres shall be numbered. The marks at the centimetre divisions shall extend over half the breadth and those at the five centimetre division over the full breadth of the measures. A cross mark shall be provided at every 25 cm, excluding the one metre and two metre graduations. (See Fig. 21) Last and first marks shall coincide with the end faces.

The graduation shall be on one side of the measures only.

(d) Permissible error —The error on the length between any two consecutive five centimetre graduation marks shall not exceed + 1 mm, and further the error from the beginning of the measures to any graduation marks shall not exceed 2 mm, for 2 metre bar, 1 mm for 1 metre bar and 0.5 mm for half metre bar provided that the errors on the full length of the measure shall not exceed the following limits :

Denomination
Verification
Inspection
Excess
Deficiency
Excess
Deficiency
2 m
4 mm
2 mm
4 mm
4 mm
1 m
2 mm
1 mm
2 mm
2 mm
0.5 mm
1 mm
0.5 mm
1 mm
1 mm

(e) Provision for stamping —Each measure shall be provided at each end with a metal tip not less than 1 cm in width, securely riveted with two rivets at each end, as shown in Fig. 21 for receiving the Legal Metrology Officer's stamp. The width of the tips shall be included in the total length of the measure.

5. Manufacture and finish

(a) The measure shall be evenly finished and shall be reasonably straight.

(b) In the case of metallic measures, the graduation marks and the cross marks shall be legible and deep enough to ensure indelibility over a reasonably long period of use, but not so deep as to make the measures liable to be easily bent. In the case of wooden measures, the markings shall be finished neatly, sharply and legibly, in a colour contrasting with the wood finish. They shall be visible from a distance and shall remain indelible over a reasonably long period of use.

6. Marking

(a) The denomination shall be stamped on the ungraduated side of the measure at about one-third of the total length from the beginning of the measure and the manufacturer's name or trade mark at a similar distance from the end of the measure. In the case of wooden measures, the markings shall be finished in the same manner as the graduations.

(b) In indicating the denominations the numerals shall be preceded by the word ‘…….' and followed by metre. The size of numerals and letters, indicating denominations of the measures shall be twice the size of the letters indicating the manufacturer's name or trade mark.

(c) The end of the measure shall be marked on the graduated side with the International form of Indian numeral indicating the denomination, preceded and followed by the letters ‘………..' and ‘m'.

Note: The word and abbreviation ‘……….' or ‘……….' may be indicated in the regional script.

PART V
FOLDING SCALES

1. General

This Part deals with wooden folding scales.

2. Denominations

The denominations of folding scales shall be 1 m and 0.5 m.

3. Materials

(a) The scales shall be made from strips or sheets of wood. They shall be reasonably uniform, in width and thickness throughout the entire length.

(b) The scales shall be made of any one of the following species of timbers:—

(i) Boxwood ( Buxus sempervirens )

(ii) Gardenia ( Gardenia sp )

(iii) Parrotia ( Parrotia jucquemontiana ) ( Randia dumetorum )

(iv) Dudhi ( Wrightia sp )

(v) Bamboo.

(vi) Haldu ( Adina cordifolia Hoock f. )

(vii) Kalam ( Mitragyna parvifolia korth )

(viii) Kuthan ( Hymenodictyon excelsum wall )

(ix) Gamri ( Gmelina abrorea Linn )

(c) The timber shall be thoroughly seasoned and radially sawn. The moisture content of the timber shall be between 8 and 12 per cent. The timber shall be free from knots, cracks, sap wood, snakes and other visible defects such as decay, insect attack, etc. and shall be fairly straight-grained.

4. Manufacture

(a) General —The scales shall be reasonably straight and flat, the edges parallel to each other and the ends reasonably square.

(b) No point on any of the edges shall be more than 0.5 mm distant from the straight line connecting its extremities. No point on the surface of a scale shall be more than 0.5 mm distant from the plane of the surface.

(c) The scales shall consist of four pieces hinged together and it shall be an end measuring scale. (First and last graduation shall be the end face). The joints shall work smoothly without undue play and shall be sufficiently free from the folds to be opened and closed without strain. The brass caps shall be closely fitted and strongly secured to the blades. They shall be made flush with the sides of the scales.

(d) A protective layer of suitable lacquer or varnish or any other suitable material shall be provided.

5. Dimensions

The principal dimensions of the scale blanks shall be as follows:—

Length of graduated part (m)
Width max. (mm
Min. (mm)

Thickness (mm)

0.5
15.0
14.5
4 ± 1
1
20.0
19.0
5 ± 1

6. Graduations

(a) Graduation marks shall be made at every millimetre with a longer line at every 5 mm and centimetre. The length of the graduation lines shall be as follows:—

cm marks 6 mm
5 mm marks 4 mm
1 mm marks 2.5 mm

(b) The lines shall be fine and clear, of uniform depth and thickness, and perpendicular to the edges. The thickness of lines shall be not more than 0.2 mm for stamped scales and 0.1 mm for engine divided scales. The lines shall be of sufficient depth to be legible and indelible.

(c) The lines shall be filled in black and natural background or with a suitable colour which shall contrast with the colour of the base to ensure legibility.

(d) Every centimetre shall be numbered in international form of Indian numerals. The height of the figures shall be between 2.0 and 2.5 mm.

7. Permissible error

The cumulative error for the entire graduated part shall not exceed + 0.50 mm. Further, over any 10 cm length scale, the error shall not exceed + 0.2 mm.

8. Marking

(a) The denomination shall be stamped on the ungraduated side of the measure at a distance about one-third of the total length from the beginning of the measure. The manufacturer's name or trade mark shall be indicated indelibly at the same distance from the other end of the measure. The markings shall be finished in the same manner as the graduations.

(b) In indicating the denominations the numerals shall be preceded by the word ^ehVj* and followed by ‘metre'.

Note: The word ^ehVj* may be indicated in the regional script.

9. Stamping

The Legal Metrology Officer's seal shall be affixed either on the metal strip at the ends or the central hinge as may be convenient.

[ PART VI
FABRIC OR PLASTIC TAPE MEASURE

1. General

(a) This Part deals with fabric or plastic tape measures, which are used for measurements, where the use of rigid length measures is not convenient or practicable.

(b) Tape measures of 0.5 m to 5 m, made of materials specified in clause 4(b), are intended to be used for measurements required in the tailoring trade, anatomical measurements or household measurements. Tape measures of 5 m and above made of materials specified in clause 4(c) are intended to be used for measurements of buildings, roads, timber and timber products and for other similar measurements but not for measurements of land, storage tanks, fermentation vats and other similar measurements.

2. Classes of accuracy

Fabric or plastic tape measure shall be divided into three classes of accuracy, namely, Class I, Class II and Class III, in accordance with their accuracy.

3. Nominal lengths

Fabrics or plastic tape measures shall be made in nominal lengths of 0.5 m, 1 m, 1.5 m, 2 m, 3 m, 4 m, 5 m or multiples of 5 metres, provided that the maximum nominal length shall not exceed 100 metres.

Note: The nominal length of a fabric or plastic tape measure is the distance at the reference temperature of 20 o C between the initial and terminal graduation lines, when the tape measure is stretched, in the wet or dry condition, and without friction on a horizontal plane surface, under an extension of 20 newtons. The length so measured shall be equal, within the limits of maximum permissible errors, to the nominal length of the tape measure.

4. Material

(a) The materials used shall be adequately strong, stable and resistant to atmospheric conditions under the normal conditions of use and shall comply with the following requirements:—

(i) When ordinarily used at temperatures between + 8 o C of the reference temperature, the variation in length of the tape measure shall not exceed the maximum permissible error.

(ii) When used with a change of + 10 per cent in the tension, the variation in length of the tape measure shall not exceed the maximum permissible error.

(b) Tape measures of nominal length 0.5m to 5m:

(i) The tape measure may be made from a suitable fabric or plastic material.

(ii) The fabric shall be coated with suitable paints, enamels or other suitable coating so as to give the tape measure a good finish. All coatings shall be non-cracking and water resistant.

(c) Tape measure of nominal length above 5 m:

(i) If made from fabrics, the fabric may be reinforced length-wise with rust-proof and rigid wires of metal or other equivalent material.

(ii) If made from plastic materials, the tape measure shall be reinforced length-wise by means of rust-proof and rigid wires of metal or glass fiber.

(iii) If made from any other material, the tape measure shall satisfy the conditions specified in clause 4(a).

5. Manufacture

(a) General

(i) Tape measures shall be well-made, robust and carefully finished.

(ii) The cross section of the tape measures shall have such dimensions and shape that, under normal conditions of use it allows the tape measure to have the accuracy specified for its class.

(iii) Tape measures shall be so made that when they are stretched over a plane surface their edges are practically straight and parallel.

(iv) The rings, winding, devices or other devices shall be attached to the tape in such a manner that they do not cause any inaccuracy or permanent deformation in the tape.

(b) Tape measures of nominal length 0.5m to 5m:

(i) Tape measures of nominal length 0.5m to 5m shall have a width of not less than 5mm and not more than 25 mm.

(ii) If not wound on a spool or in a case, both the ends of the tape measure shall be reinforced with plastic or metal strips, of the same width as the tape measure, over a length of not less than 10mm or more than 100 mm.

(iii) If wound on a spool or in a case, the tape measure shall have a metal ring or other device securely attached to the outer end of the tape measure. A device, retraction or winding of the tape shall be provided.

(c) Tape measure of nominal length above 5m:

(i) The tape measures shall have a width of not less than 10 mm and a thickness between 0.3 and 0.6 mm.

(ii) A metal ring shall be securely attached to the outer end of each tape measure. The ring shall be securely fastened to the tape measure by a metal strip of the same width as the tape.

(iii) The outer end of the tape measure shall be reinforced over a length of not less than 100 mm by a strip of leather or other suitable material of the same width as the tape measure. The strip shall pass round the inner end of the ring and under the metal strip.

Note: This strip, besides serving as a protective device shall also be utilised for affixing the stamp of verification.

(iv) The tape measure shall be rolled into a suitable container or wound on a winding device made of metal, plastic, leather or other suitable material.

6. Graduations

(a) General requirements :

(i) Graduation lines shall be clear, uniform, indelible and so made as to ensure easy and unambiguous reading.

(ii) The value of the graduations shall be of the form 1 x 10 n , 2 x 10 n or 5 x 10 n , the exponent “n” being positive or negative whole number or zero. The value of the graduation, however, shall not exceed :

1 cm, on measures of nominal length less than or equal to 2m,
10 cm, on measures of nominal length more than 2 m, but less than 10m,
20 cm, on measures of nominal length more than 10 m, but less than 50m,
50 cm, on measures of nominal length equal to or more than 50m.

(iii) Graduation lines shall be reasonably straight, perpendicular to the axis of the tape measures and of uniform thickness throughout the length.

(iv) Graduations lines shall be so made that they form a clear and distinct scale and their thickness does not cause any inaccuracy of reading.

(b) Tape measures of nominal length 0.5m to 5m:

(i) The zero graduation line may be located at the outer end of the ring or other device or may commence on the tape itself at a length equal to or greater than 50mm from the outer end of the ring or other device.

(ii) The tape measures may be graduated throughout at every millimetre or every 5 mm.

(iii) The graduation lines at every 10mm shall be marked in such a manner that there is no confusion between the 10 mm lines and the millimetre or 5 mm lines.

(iv) The tape measures may be graduated on one side or both the sides. If the tape is graduated on one side, the manufacturer's name, trade mark, advertisement or other similar matter may be printed on the ungraduated side of the tape measure.

(c) Tape measures of nominal length above 5 m:

(i) The zero graduation line may be located at the outer end of the metal ring or on the tape itself, at a length equal to or greater than 100mm from the outer end of the ring.

(ii) The tape measure may be graduated at every millimetre, every 5 millimetre or every 10 millimetre.

(iii) The graduation lines at every 10 mm shall be marked in such a manner that there is no confusion between the 10 mm graduation lines and the millimetre or 5 mm graduation line.

(iv) The graduation lines at every 10m shall have a length approximately half the width of the tape.

(v) Every graduation line at 50 mm shall have the same length as the graduation line at 10 mm but may have an arrow at its end. This requirement shall not apply to tape measures graduated at every millimetre.

(vi) The zero graduation line, the graduation lines at every 100 millimetres and at every metre shall have a length equal to the width of the tape.

7. Numbering

(a) General requirements :

(i) The numerals shall be indicated clearly, uniformly and indelibly and shall be easily and unambiguously legible.

(ii) The places, dimensions, shape, colour and contrast of the numerals shall be suitable for the scale and graduation lines to which they relate.

(iii) The numerals shall be marked parallel to or perpendicular to the axis of the tape measure depending upon the intended manner of use of the measure.

(b) On tape measures of nominal length 0.5 m to 5 m:

(i) Every graduation line at 10 mm shall be marked with the complete number of centimetre.

Explanation: The graduation number marked may be, for example 122 and not 22 after completion of one metre.

(ii) The height of the numerals shall not exceed two-thirds the width of the tape measures.

(c) On tape measures of nominal length above 5m.

(i) The graduation lines at every 100 mm and at every metre shall be numbered. The numerals shall have a height of not more than two-thirds of the width of the tape.

(ii) the metre graduations shall be accompanied by the symbol ‘m' and, if required,
^eh* .

Note: The abbreviation ^eh* may be indicated in the regional script.

(iii) After the graduation line at one metre, every graduation line at 100 mm may be marked with an additional numeral indicating the completed number of metres. This numerals, if provided, may be located just above, below or in line with the numeral of the 100 mm graduation line. The height of the numeral may be approximately half the height of the numerals indicating 100 mm.

8. Maximum permissible error

(i) On verification, under the conditions specified in clause 2, the error on the length between the axis of any two graduation lines shall not exceed :

for Class I + (0.1 + 0.1L) mm
for Class II + (0.3 + 0.2L) mm; and
for Class III + (0.6 + 0.4L) mm;

Where L is the length between the two graduation lines concerned, expressed in metres, rounded off to the next higher whole number of metres.

(ii) The maximum permissible error on tape measures on inspection shall be twice that specified for verification, the methods of verification remaining unchanged.

(iii) Tape measure of nominal length 0.5 m to 5m shall belong to accuracy Class II or Class III.

(iv) Tape measures of nominal length above 5m shall belong to accuracy Class I, Class II or Class III.

9. Markings

(a) Tape measures of nominal length 0.5 m to 5m:

The tape measures and the case or container, if provided shall be marked at a suitable place with the following markings :

(i) nominal length in metres.

(ii) manufacturer's name or trade mark or both.

(iii) class of accuracy II or III in an oval.

(iv) an indication of the location of zero on the scale.

(v) model approval number issued by the Central Government.

(b) Tape measure of nominal length above 5 m:

The tape measure and the case or container or other device, where provided shall be marked near the zero graduation line and on the container, case or other device with the following markings:—

(i) nominal length in metres.

(ii) manufacturer's name or trade mark or both.

(iii) class of accuracy : I, II or III in an oval.

(iv) an indication of the location of zero on the scale.

(v) model approval number issued by the Central Government.

(c) The inscription shall be clearly visible and legible.

(d) Advertising inscriptions, if made, shall be carried out of such a manner that they did not intrude in any way with the use of the tape measure.

10. Sealing

The stamp of verification shall be affixed on the metal, plastic, leather or other strip provided at the beginning of the tape measure.

PART VII
STEEL TAPE MEASURES

1. General

This Part deals with steel tape measures which are used for measurements where the use of rigid length measures is not convenient or practicable.

2. Classes of accuracy

Steel tape measures shall be divided into three classes, namely, Class I, Class II and Class III, in accordance with their accuracy.

3. Nominal lengths

The tape measures shall be made in nominal lengths of 0.5 m, 1 m, 1.5 m, 2 m, 3 m, 4 m, 5 m or multiples of 5 m, provided that the maximum nominal length not exceed 200m.

Note: The nominal length of a steel tape measure is the distance at the reference temperature of + 20 o C, between the initial and terminal graduation lines, when the tape measure is stretched, without friction, on a horizontal plane surface, under a tension of 50 newtons. The length so measured shall be equal, within the limits of maximum permissible errors, to the nominal length of the tape measures.

4. Materials

(a) The materials used shall be adequately strong, stable and resistant to environmental influences under normal conditions of use and shall comply with the following requirements:

(i) when ordinarily used at temperatures between + 10°C of the reference temperature, variation in length of the tape measure shall not exceed the maximum permissible error;

(ii) when used with a change of + 10% in the tensions, the variation in length of the tape measure shall not exceed the maximum permissible error.

(b) The tape measure shall be made from steel or stainless steel.

5. Manufacture

(a) Tape measures shall be well made, robust and carefully finished. (See Figs. 22 to 26).

(b) The cross section of the tape measures shall have such dimensions and shape that, under normal conditions of use, it allows the tape measures to have the accuracy specified for its class.

Note : It is recommended for guidance of manufacturer and users that tape measure may have a width of not less than 5 mm and a maximum thickness of 0.4 mm.

(c) The steel tape measure shall be so made that when it is stretched on a plane surface, the edges are practically straight and parallel.

(d) At the zero end, tape measures shall be provided, with a ring or other device for facilitating withdrawal. The ring or other device, when provided, shall be fastened to the tape measure by a metal strip of the same width as the tape.

(e) The tape measures shall be capable of being wound into suitable container or other winding device of robust construction and made of metal, plastic, leather or other suitable material.

(f) The winding devices shall be so designed that they do not cause any inaccuracy or permanent deformation in the tape.

(g) The edges of tape measures shall be slightly rounded.

(h) The tape measure shall be provided with rust proof coating and shall be free from burrs.

6. Graduations

(a) General requirements

(i) Graduation lines shall be clear, uniform, indelible and so made as to ensure easy and unambiguous reading.

(ii) The value of the graduations shall be of the form 1 x 10 n , 2 x 10 n or 5 x 10 n metre where the exponent ‘n' being a positive or negative whole number or zero.

The value of the graduations, however, shall not exceed :

1 cm, on measures of nominal length less than or equal to 2 m,
10 cm, on measures of nominal length more than 2 m but less than 10 m,
20 cm, on measures of nominal length more than 10 m, but less than 50 m,
50 cm, on measures of nominal length equal to or more than 50 m.

(iii) Graduation lines shall be reasonably straight, perpendicular to the axis of the tape measure, and of uniform thickness throughout their length.

(iv) Graduation lines shall be so made that they form a clear and distinct scale and that their thickness does not cause any inaccuracy of reading.

(b) Tape measures above 5 m to 200 m shall be graduated only on one side. Tape measures of 0.5 m to 5 m may be graduated on both sides (Only metric scale).

(c) The graduated lines, numbers and other markings shall be either in relief, engraved, typographically printed or made in any other suitable manner.

(d) The zero of the scale may be located at the outer or inner edge of the ring or other device, or may also be located on the tape measure itself, at a length equal to or greater than:

(i) 50 mm from the outer end of the ring or other device, in the case of tape measures of nominal length 0.5 m to 5 m; and

(ii) 100 mm from the outer end of the ring or other device, in the case of tape measures of nominal lengths above 5 m.

(e) Tape measure of denominations 0.5m to 5m may be graduated throughout at every millimetre, every 5 millimetre or every 10 millimetre.

(i) The graduation lines at every 10mm shall be marked in such a manner that there is no confusion between the 100 mm graduation lines and the millimetre or 5 mm graduation lines.

(ii) In the case of tape measures graduated at every 5 mm or 10 mm, not less than the first 100 mm shall be subdivided into millimetre.

(f) In the case of tape measures of nominal length above 5 m, every graduation line at 50 mm shall have the same length as the graduation line at 10 mm but may have an arrow at its end. This requirement shall not apply to tape measures graduated at every millimetre.

(g) The thickness of the graduation lines shall not exceed the following limits :

0.4 mm in the case of Class I and Class II tape measures, and 0.5 mm in the case of Class III tape measures.

(h) In the case of tape measures of nominal length 0.5m to 5m, the graduation lines may have a length between one-fourth and full width of the tape, depending upon convenience. In the case of tape measures of nominal length above 5 m, the length of the graduation lines may be as follows:—

(i) for millimetre graduation lines, about one-third of the width of the tape;

(ii) for 5 millimetre graduation lines, about half the width of the tape;

(iii) for 10 millimetre graduation lines, about two-thirds the width of the tape; and

(iv) for 100 millimetre graduation lines and for metre graduation lines as well as for the zero graduation lines, equal to the width of the tape.

7. Numbering

(a) General requirements :

(i) The numerals shall be indicated clearly, uniformly and indelibly and shall be easily and unambiguously legible.

(ii) The places, dimensions, shape, colour and contrast of the numerals shall be suitable for the scale and graduation lines to which they relate.

(iii) The numerals shall be marked parallel to or perpendicular to the axis of the tape measure depending upon the intended manner of use of the measure.

(b) The following graduation lines shall be numbered :

10 mm, for tape measure of nominal length 0.5 to 5 m, 100 mm for tape measure of nominal length exceeding 5 m.

(c) The metre graduation lines shall be numbered and accompanied by the symbol ‘m' and if required.

Note: The abbreviation ‘……….' may be indicated in the regional script.

(d) In the case of the tape measure of nominal length of 0.5 m to 5 m, the height of the numerals shall be such as would facilitate the reading of the measurement without ambiguity.

(e) In the case of tape measures of nominal length 5 m and above, after the graduation line at one metre, every graduation line at 100 mm may be marked with an additional numeral indicating the completed number of metres. This numeral, if provided, may be located just above or in line with the numeral of the 100 mm graduation line. The height of this numeral may be approximately half the height of the numerals indicating 100 mm.

(f) In the case of tape measures of nominal length 5 m and above the height of the numerals, except those given in sub-clause (e) of clause 7 may be :

(i) about 1/3 of the width of the tape, for 10 mm graduation lines,

(ii) about 1/2 of the width of the tape, for 100 mm graduation lines, and

(iii) about 2/3 of the width of the tape, for metre graduation lines.

(g) If tapes of 0.5 m to 5 m are contained in special container may be marked with its dimension, for example, 50 mm, to facilitate measurement of internal dimensions.

8. Maximum permissible error

(a) On verification, under the conditions specified in clause 2, the error on the length between the axis of any two graduation lines shall not exceed :

for Class I + (0.1 + 1L) mm,
for Class II + (0.3 + 0.2L) mm, and
for Class III + (0.6 + 0.4L) mm,

where L is length between two graduation lines concerned, expressed in metres, rounded off to the next higher whole number of metres.

(b) The maximum permissible error on tape measures on inspection shall be twice that specified for verification, the method of verification remaining unchanged.

(c) Steel tape measures of nominal length 0.5 m to 5 m shall belong to accuracy Class I or Class II.

(d) Tape measures of nominal length above 5 m shall belong to accuracy Class I, Class II or Class III.

9. Markings

(a) The steel tape measures shall be marked at a suitable place near the end and on the container, where provided with the following markings :

(i) nominal length in metre,

(ii) an indication of the location of the zero of the scale,

(iii) the manufacturer's name or trade mark or both,

(iv) class of accuracy : I, II or III in an oval,

(v) model approval number issued by the Central Government.

(b) The inscriptions shall be clearly visible and legible.

(c) Advertising inscriptions, if made, shall be carried out in such a manner that they do not intrude in any way with the use of the tape measure.

10. Sealing

The stamp of verification shall be affixed on the metal, plastic, leather or other strip provided at the beginning of the tape measure.

PART VIII
SURVEYING CHAINS

1. General

This Part deals with link type surveying chains of 20 m and 30 m lengths for land measurement.

2. Definitions

(a) Surveying chain—An instrument for measuring the surface distance between two points.

(b) Length of chain—The distance between the outside edges of the handles when fully stretched.

(c) Tallies—Metallic tags or indicators of distinctive pattern fixed at (various points) of the chain, to facilitate quick reading of fractions of a chain.

3. Material

The different components of the chains shall be made from the materials mentioned against each.

Components

Material

Handle

Eye Bolt Collar

Ring
Link, Small
Link, Large
Link, Connecting
Tally
Indicating ring

Brass Castings

Brass suitable for free cutting and high speed machine work

Galvanised mild steel wire 4 mm.

Brass sheet or galvanized sheet
Brass wire

4. Constructional details

(a) The nomenclature of the different parts of the chain and their dimensions shall be as indicated in Figs. 27, 28 & 29.

(b) The tallies shall be fixed at every fifth metre along the chain. Small rings shall be fixed at every metre, except where tallies are attached. Tallies shall have distinctive shapes depending on their position in the chain as shown in Figs. 27 and 28.

(c) Connecting links between two large links shall be oval in shape, the central one being a circular ring.

(d) To facilitate holding the arrows (chain pains) in position with the handle of the chain, a groove shall be cut on the outside surface of the handle as shown in Fig. 29. The radius of the groove shall correspond to the radius of the arrows.

(e) The handle joint shall have flexibility in order that it may be possible to swivel the handle round the eye bolt. A swivel may also be provided at the middle of the chain.

5. Permissible error

(a) When measured with a tension of 80 newtons every metre length shall be correct with an error not exceeding + 2 mm.

The overall length of the chains shall be correct within the following limits of error :

20 metre chains + 5mm
30 metre chains + 8 mm

(b) The permissible errors shall be the same for verification and inspection.

Explanation: Nominal distance between the centres of the circular links containing the small rings or tallies shall define the distance.

6. Marking

(a) The tallies used for marking the distances in chain shall be marked with letters ^ehú* and ‘m' (See Fig. 29).

(b) The length of the chain, 20 m or 30 m, as the case may be, shall be indelibly marked over the handle (See Fig. 29).

(c) The chains shall be indelibly marked, on the reverse side of the surface of the handle having the denominations with the manufacturer's name or trade mark.

Note: The abbreviation ^eh-*  may be indicated in the regional script.

7. Provision for stamping

A metal label or disc shall be permanently attached to the handled at the beginning of each chain for the verification of stamp.

PART IX
TAPES FOR USE IN MEASUREMENT OF OIL QUANTITIES

1. General

This Part covers the requirements of tape with the dip weight attached to it and to be used in gauging petroleum, petroleum products and other oils.

2. Definitions

A dip tape shall mean essentially a graduated steel tape in one continuous length used in conjunction with a dip weight.

3. Denominations

The tape shall be of the denominations 5, 10, 15, 20, 25 and 50 metres.

4. Material

(a) Tape—The steel used shall have a minimum tensile strength of 1500 M Pa.

(b) Dip weights or dip bobs—The dip weights shall be made of brass or other non-sparking or low sparking material, sufficiently hard to resist damage by contact with steel.

5. Dip tape

(a) The dip tape shall be of the following dimensions :

Width : 13 mm or 16 mm
Thickness : Between 0.20 and 0.30 mm
Length : One continuous piece of sufficient length for the purpose required. The tape shall be longer than the distance between the dip reference point and the bottom of the container.

b) Graduations

(i) The tape shall be marked legibly and indelibly on one side only with a line at every millimetre or five millimetres, centimetre, decimetre and metre. The height of marking lines shall be as follows :

Unit of graduation

Approximate height of graduation mm

Millimetre
4
Five millimetres
6
Centimetre
8
Decimetre
Full width of the tape
Metre
Full width of the tape

(c) The tape shall be so made that it is capable of being wound on a drum and held in a winding frame or case.

(d) The free end of the tape shall be fitted with the dip weight or arrangements provided for attaching the dip weight.

6. Dip weights

(a) Dip weights shall be of two types, light and heavy, and shall be of cylindrical torpedo shape. The dimensions for light and heavy dip weights shall be as shown in Fig. 30.

(b) The light type may either be fixed permanently to the tape or attached separately to it by any suitable device.

(c) The heavy type shall be attached to the tape by a swivel hook (See Fig. 31).

(d) The dip weight shall have the lengths of graduation and weights given below :

Light
Heavy

Length of graduations
from bottom weight

150 mm
150 mm
700±50 g
1500±50 g

(e) The dip weight shall be graduated in a manner similar to the tape.

(f) The graduations on the dip weight shall begin from its bottom and shall be carried over in such a manner that when the dip weight is attached to the tape the graduations are continuous from the weight to the tape.

7. Permissible error

The error in the length of the tape supported on horizontal surface with a tension of 50 newtons shall not exceed the following limits :

(a)Between any two adjoining
mm and cm lines

Not more than ±0.2 mm

 

Not more than ±0.4 mm
(b) Between any two adjoining
decimetre and metre lines

(c) From zero to the points specified below :

(i) One metre mark
_______
±0.4 mm
(ii) Two metre mark
_______
±0.6 mm
(iii) Five metre mark
_______
±1.0 mm
(iv) Any metre mark beyond the first five metre
± 1.0 mm for the first five metres plus 0.5 mm for each additional five metres or part thereof subject to a maximum error of 2.0 mm.

8. Marking

(a) Every centimetre, decimetre and metre shall be marked with international form of Indian numerals. The decimetre and metre numerals shall be in bold type. The metre divisions shall, in addition, bear the designation ‘……….' or ‘m' or both. The end of the tape measure shall be marked with word ‘…………' or ‘metre' or both.

(b) On the ungraduated side and on the case of each tape and also on the dip weight, the name or trade-mark of the manufacturer and the denominations shall be legibly marked. In addition, direction of winding shall also be legibly marked on the case or reel. Suitable provisions shall be made for Legal Metrology Officer's stamps on the dip weight and the tape.

(c) Every dip weight and dip tape shall be suitably marked to identify them with each other.

Note: The word ‘……………..' and abbreviation ‘……….' may be indicated in the regional script.

SEVENTH SCHEDULE
[ Rule 13 ]
“HEADING A”
SPECIFICATION FOR NON-AUTOMATIC WEIGHING INSTRUMENTS
PART I
TERMINOLOGY

1. General definitions

(1) Weighing instrument

Measuring instrument that serves to determine the mass of a body by using the action of gravity on this body.

The instrument may also be used to determine other quantities, magnitudes, parameters or characteristics related to mass.

According to its method of operation, a weighing instrument is classified as an automatic or non-automatic instrument.

(2) Non-automatic weighing instrument

Instrument that requires the intervention of an operator during the weighing process, for example to deposit on or remove from the receptor, the load to be measured and also to obtain the result.

The instrument permits direct observation of the weighing results, either displayed or printed; both possibilities are covered by the word “indication”.

Note: Terms such as “indicate”, “indicating component” and their derivatives do not include printing.

A non-automatic weighing instrument may be

—graduated or non-graduated,

—self-indicating, semi-self-indicating or non-self indicating.

Note: In this specification, a non-automatic weighing instrument is called an “instrument”.

(i) Graduated instrument
Instrument allowing the direct reading of the complete or partial weighing result.

(ii) Self-indicating instrument
Instrument in which the position of equilibrium is obtained without the intervention of an operator.

(iii) Semi-self indicating instrument
Instrument with a self-indication weighing range, in which the operator intervenes to alter the limits of this range.

(iv) Electronic instrument
Instrument equipped with electronic devices.

(v) Instrument with price scales
Instrument that indicates the price to pay by means of price charts or scales related to a range of unit prices.

(vi) Price computing instrument
Instrument that calculates the price to pay on the basis of the indicated mass and the unit price.

(vii) Price-labelling instrument
Price computing instrument that prints the weight value, unit price and price to pay for prepackages.

(viii) Self-service instrument
Instrument that is intended to be operated by the customer.

2. Construction of an instrument

In this specification the term “device” is used for any means by which a specific function is performed, irrespective of the physical realization, e.g. by a mechanism or a key initiating an operation; the device may be a small part or a major portion of an instrument.

(1) Main device

(i) Load receptor or pan
Part of the instrument intended to receive the load.

(ii) Load transmitting device
Part of the instrument for transmitting the force produced by the load acting on the load receptor, to the load-measuring device.

(iii) Load-measuring device
Part of the instrument for measuring the mass of the load by means of an equilibrium device for balancing the force coming from the load transmitting device, and an indicating or printing device.

(2) Module

Part of an instrument which performs a specific function, can be examined separately and is subject to specified partial error limits.

(3) Electronic parts

(i) Electronic device
A device employing electronic subassembly and performing a specific function. An electronic device is usually manufactured as a separate unit and can be independently tested.

Note : An electronic device, as defined above, may be a complete instrument (e.g. instrument for direct sales to the public) or parts of an instrument (e.g. printer, indicator)

(ii) Electronic sub-assembly
A part of an electronic device, employing electronic components and having a recognizable function of its own. (e.g. A/D converter, display matrix).

(iii) Electronic component
The smallest physical entity that uses electron or hole conduction in semi-conductors, gases or in a vacuum.

(4) Indication device (of a weighing instrument)

Part of the load measuring device on which the direct reading of the result is obtained.

(i) Indicating component
Component indicating the equilibrium and/or the result on an instrument with one position of equilibrium it indicate only the equilibrium (so-called zero).
On an instrument with several positions of equilibrium it indicates both the equilibrium and the result. On an electronic instrument, this is the display.

(ii) Scale mark
A line or other mark on an indicating component corresponding to a specified value of mass.

(iii) Scale base
An imaginary line though the centres of all the shortest scale marks.

(5) Auxiliary indicating devices

(i) Device for interpolation of reading (Vernier)
Device connected to the indicating element and sub-dividing the scale of an instrument, without special adjustment.

(ii) Complementary indicating device
Adjustable device by means of which it is possible to estimate, in units of mass, the value corresponding to the distance between a scale mark and the indicating component.

(iii) Indicating device with a differentiated scale division
Digital indicating device of which the last figure after the decimal sign is clearly differentiated from other figures.

(6) Extended indicating device

A device temporarily changing the actual scale interval (d) to a value less than the verification scale interval (e) following a manual command.

(7) Supplementary devices

(i) Levelling device

Device for setting an instrument to its reference position.

(ii) Zero setting device

Device for setting the indication to zero when there is no load on the load receptor.

(a) Non automatic zero setting device
Device for setting the indication to zero by an operator.

(b) Semi automatic zero setting device
Device for setting the indication to zero automatically following a manual control.

(c) Automatic zero-setting device
Device for setting the indication to zero automatically without the intervention of an operator.

(d) Initial zero-setting device
Device for setting the indication to zero automatically at the time the instrument is switched on and before it is ready for use.

(iii) Zero tracking device

Device for maintaining the zero indication within certain limits automatically.

(iv) Tare device

Device for setting the indication to zero when a load is on the load receptor;
without altering the weighing range for net loads (additive tare device); or
reducing the weighing range for net loads (subtractive tare device).
It may function as:
a non-automatic devices (load balanced by an operator);
a semi-automatic device (load balanced automatically following a single manual command);
an automatic device (load balanced automatically without the intervention of an operator).

(a) Tare balancing device : Tare device without indication of the tare value when the instrument is loaded.

(b) Tare weighing device : Tare device that stores the tare value and is capable of indicating or printing it whether or not the instrument is loaded.

(v) Preset tare device

Device for subtracting a preset tare value from a gross or net weight value and indicating the result of the calculation. The weighing range for net loads is reduced accordingly.

(vi) Locking device

Device for immobilizing all or part of the mechanism of an instrument.

(vii) Auxiliary verification device

Device permitting separate verification of one or more main devices of an instrument.

(viii) Selection device for load receptors and load measuring devices

Devices for attaching one or more load receptors to one or more load measuring devices, whatever intermediate load transmitting device are used.

(ix) Indication stabilizing device

Device for maintaining a stable indication under given conditions.

3. Metrological characteristics of an instrument

(1) Weighing capacity (Max)

(i) Maximum weighing capacity, not taking into account the additive tare capacity.

(ii) Minimum capacity (Min)
Value of the load below which the weighing results may be subject to an excessive relative error.

(iii) Self-indication capacity
Weighing capacity within which equilibrium is obtained without the intervention of an operator.

(iv) Weighing range
Range between the minimum and maximum capacities.

(v) Extension interval of self indication
Value by which it is possible to extend the range of self-indication within the weighing range.

(vi) Maximum tare effect (T= + ..., T = -...)
Maximum capacity of the additive tare device or the subtractive tare device.

(vii) Maximum safe load (Lim)
Maximum static load that can be carried by the instrument without permanently altering its metrological qualities.

(2) Scale divisions

(i) Scale spacing (instrument with analogue indication)
Distance between any two consecutive scale marks, measured along the scale base.

(ii) Actual scale interval (d)
Value expressed in units of mass of,—
the difference between the values corresponding to two consecutive scale marks, for analogue indication, or
the difference between two consecutive indicated values, for digital indication.

(iii) Verification scale interval (e)
Value expressed in units of mass, used for the classifications and verification of an instrument.

(iv) Scale interval of numbering
Value of the difference between two consecutive numbered scale marks.

(v) Number of verification scale intervals (single interval instrument)
Quotient of the maximum capacity and the verification scale interval:

n= Max/e

(vi) Multi-interval instrument
Instrument having one weighing range which is divided into partial weighing ranges each with different scale intervals, with the weighing range determined automatically according to the load applied, both on increasing and decreasing loads.

(vii) Multiple range instrument
Instrument having two or more weighing ranges with different maximum capacities and different scale intervals for the same load receptor, each range extending from zero to its maximum capacity.

4. Metrological properties of an instrument

(1) Discrimination
Ability of an instrument to react to small variation of load.
The discrimination threshold, for a given load, is the value of the smallest additional load that, when gently deposited on or removed from the load receptor causes a perceptible change in the indication.

(2) Repeatability
Ability of an instrument to provide results that agree one with the other when the same load is deposited several times and in a practically identical way on the load receptor under reasonably constant test conditions.

(3) Durability
Ability of an instrument to maintain its performance characteristics over a period of use.

(4) Warm-up time
The time between the moment power is applied to an instrument and the moment at which the instrument is capable of complying with requirements.

5. Indications and errors

(1) Methods of indication

(i) Balancing by weights :
Value of metrological controlled weights that balance the load (taking into account the reduction ratio of the load).

(ii) Analogue indication :
Indication enabling the evaluation of the equilibrium position to a fraction of the scale interval.

(iii) Digital indication :
Indication in which the scale marks are composed of a sequence of aligned figures that do not permit interpolation to fractions of the scale interval.

(2) Weighing results

Note: The following definitions apply only when the indication has been zero before the load has been applied to the instrument.

(i) Gross value (G) :
Indication of the weight of a load on an instrument, with no tare or preset tare device in operation.

(ii) Net value (N) :
Indication of the weight of a load on an instrument after operation of a tare device.

(iii) Tare value (T) :
The weight value of a load, determined by a tare weighing device.

(3) Other weight values

(i) Preset tare value (PT) :
Numerical value, representing a weight, that is introduced into the instrument.
“Introduced” includes such as keying in, recalling from a data storage, or inserting via an interface.

(ii) Calculated net value :
Value of the difference between a gross or net weight value and a preset tare value.

(iii) Calculated total weight value :
Calculated sum of more than one weight value and/or calculated net value.

(4) Reading

(i) Reading by simple juxtaposition
Reading of the weighing result by simple juxtaposition of consecutive figures giving the weighing result, without the need of calculation.

(ii) Overall inaccuracy of reading
The overall inaccuracy of reading of an instrument with analog indication is equal to the standard deviation of the same indication, the reading of which is carried out under normal conditions of use by several observers.
It is customary to make at least ten readings of the results.

(iii) Rounding error of digital indication
Difference between the indication and the result the instrument would give with analog indication

(iv) Minimum reading distance
The shortest distance that an observer is able to freely approach the indicting device to take a reading under normal conditions of use.
This approach is considered to be free for the observer if there is a clear space of at least 0.8 m in front of the indicting device. (See figure 55A)

(5) Errors
(See Figure 55-B for illustration of certain terms used)

Illustration of certain terms used

M = mass to be measured
E = error of indication

MPE1 = maximum permissible error on verification

MPE2 = maximum permissible error in service (inspection)

C = characteristic under reference conditions

C1 = characteristic due to influence factor or disturbance

C2= characteristic after durability tests

I1= intrinsic

DE = durability error

Situation 1 : Shows the error E1 of an instrument due to an influence factor or a disturbance, I1 is the intrinsic error. The fault due to the influence factor or disturbance applied equals E1 minus I1.

Situation 2 : Shows the error E2 of an instrument after the durability test. I2 is the initial intrinsic error. The durability error equals E2 minus I2 .

(i) Error (of indication)
The indication of an instrument minus the (conventional) true value of the mass.

(ii) Intrinsic error
The error of an instrument under reference conditions.

(iii) Initial intrinsic error
The intrinsic error of an instrument as determined prior to the performance and span stability tests.

(iv) Maximum permissible error
Maximum difference, positive or negative, allowed by regulation between the indication of an instrument and the corresponding true value, as determined by reference standard masses, with the instrument being at zero at no-load, in the reference position.

(v) Fault
The difference between the error or indication and the intrinsic error of an instrument.

Note: Principally, a fault is the result of an undesired change of data contained in or flowing through an electronic instrument.

(vi) Significant fault
A fault greater than e .

Note : For a multi-interval instrument, the value of e is that appropriate to the partial weighing range.

The following are not considered to be significant faults, even when they exceed  e :

- Faults arising from simultaneous and mutually independent causes in the instrument.

- Faults implying the impossibility to perform any measurement.

- Faults being so serious that they are bound to be noticed by all those interested in the result of measurement.

- Transitory faults being momentary variations in the indication which cannot be interpreted, memorized or transmitted as a measuring result.

(vii) Durability error

The difference between the intrinsic error over a period of use and the initial intrinsic error of an instrument.

(viii) Significant durability error

A durability error greater than e .

Note 1: A durability error can be due to mechanical wear and tear or due to drift and aging of electronic parts. The concept of significant durability error applies only to electronic parts.

Note 2: For a multi-interval instrument, the value of e is that appropriate to the partial weighing range.

The following are not considered to be significant durability error, even when they exceed e :

Errors occurring after a period of instrument use that are clearly the result of a failure of a device/component, or of a disturbance and for which the indication:

- cannot be interpreted, memorized, or transmitted as a measurement result/or

- implies the impossibility to perform any measurement, or

- is so obviously wrong that it is bound to be noticed by all those interested in the results of measurement.

(ix) Span stability

The capacity of an instrument to maintain the difference between the indication of weight at maximum capacity and the indication at zero over period of use within specified limits.

6. Influence and reference conditions

(1) Influence quantity

A quantity that is not the subject of the measurement but which influences the values of the measure and or the indication of the instrument.

(i) Influence factor
An influence quantity having a value within the specified rated operating conditions of the instrument.

(ii) Disturbance
An influence quantity having a value within the limits specified in this specification but outside the specified rated operating conditions of the instrument.

(2) Rated operating conditions

Conditions of use, giving the range of values of influence quantities for which the metrological characteristics are intended to lie within the specified maximum permissible errors.

(3) Reference conditions

A set of specified values of influence factors fixed to ensure valid inter-comparison of the results of measurements.

(4) Reference position

Position of the instrument at which its operation is adjusted.

7. Performance test

A test to verify whether the equipment under test (EUT) is capable of performing its intended functions.

PART II
NON-AUTOMATIC WEIGHING INSTRUMENTS

1. Scope

This specification specifies the metrological and technical requirements for non-automatic weighing instruments and will not be applicable to the following non-graduated instruments:

(1) Beam scale

(2) Counter machine

2. Principles involved

(1) Units of measurement

(i) The units of mass to be used on an instrument shall be the kilogram (kg) the milligram (mg), the gram (g) and tonne (t).

(ii) For special application e.g. trade with precious stones, the metric carat (1 carat = 0.2 g) may be used as unit of measurement. A symbol for the carat shall be “c”.

(2) Metrological requirements

The requirements apply to all instruments irrespective of their principles of measurement.

Instruments are classified according to:

- the verification scale interval,

- the number of verification scale intervals.

The maximum permissible errors are in the order of magnitude of the verification scale interval.

A minimum capacity (Min) is specified to indicate that the instrument should not be used for measuring loads below that limit.

3. Metrological requirements

(1) Principles of classification

(i) Accuracy classes
The accuracy classes for instrument and their symbols shall be as given in Table 38.

TABLE 38

Class
Symbol
Special accuracy

I

High accuracy

II

Medium accuracy
III
Ordinary accuracy
IIII

(2) Verification scale interval

(i) Verification scale interval shall be in the form
1 x 10k, 2 x 10k , 5 x 10k
k being a positive or negative whole number or equal to zero.

(ii) The verification scale interval for different types of instruments shall be as given in Table 39.

TABLE 39

Type of instrument
Verification scale interval

Graduated, without auxiliary indicating
device


Graduated, with auxiliary indicating device

Non-graduated

    e = d
e is chosen by the manufacturer according
to requirement in sub-pragraph (3) and clause (iii) of sub-aragraph (5) of this paragraph.
e is chosen by the manufacturer according to sub-paragraph (3) of this paragraph.

(3) Classification of instruments

(i) The verification scale interval, number of verification scale intervals and the minimum capacity, in relation to the accuracy class of an instrument, shall be as given in Table 40.

TABLE 40

Accuracy class
Verification scale interval e

Number of verification scale intervals
n = Max/e

Minimum
capacity
minimum
maximum
Special I
0.001 g < e
50 000*
-
100 e
High II
0.001 g < e < 0.05 g
100
100000
20 e
0.1 g < e
5000
100000
50 e
Medium III
0.1 g < e < 2 g
100
10000
20 e
5 g < e
500
10000
20 e
Ordinary IIII
5 g < e
100
1000
10 e

Note: For values of ‘e' less than 1 mg in respect of class I accuracy instruments, e shall be taken to be equal to 1 mg for the purpose of verification/inspection.

See for exception in clause (v) of sub-paragraph (5) of this paragraph.

(ii) On multiple range instruments, if the verification scale intervals are e1, e2 .... er with e1< e2 < ...<  er , Min, n and Max shall be indexed accordingly.

(iii) On multiple range instruments each range shall be treated as an instrument with one range.

(iv) For special application that are clearly marked on the instrument, an instrument may have weighing ranges in classes I and II or in classes II and III. The instrument as a whole shall then comply with the more severe requirements of sub-paragraph (9) of this paragraph applicable to either of the two classes.

(4) Additional requirements for a multi-interval instrument

(i) Partial weighing range

Each partial range (index i = 1, 2...) shall be defined by:
--its verification scale intervals ei, ei+1> ei
its maximum capacity Maxi
its minimum capacity Mini = Max(i-1) (for i = 1 the minimum capacity is Min1 1 = Min)
The number of verification scale intervals n for each partial range is equal to

ni = Maxi /ei

(ii) Accuracy class

ei and ni in each partial weighing range, and mini shall comply with the requirements given in Table 40 according to the accuracy class of the instrument.

(iii) Maximum capacity of partial weighing ranges

With the exception of the last partial weighing range, the requirements in Table 41 shall be complied with, according to the accuracy class of the instrument.

TABLE 41

Class
I
II
III
IV
Max i /e i +1
> 50 000
> 5 000
> 500

> 50

(iv) Instrument with a tare device

Requirements concerning the ranges of a multi-interval instrument apply to the net load, for every possible value of the tare.

(5) Auxiliary indicating devices

(i) Type and application

Only instruments of classes I and II may be fitted with an auxiliary indicating device, which shall be,—

a device with a rider, or
a device for interpolation of reading, or
a complementary indicating device or
an indicating device with a differentiated scale division.

These devices shall be permitted only to the right of the decimal sign.

(ii) A multi-interval instrument shall not be fitted with an auxiliary indicating device.

(iii) Verification scale interval

The verification scale interval e shall be determined by the expression

d < e < 10 d
such that e = 1 x 10k kg

k being a positive or negative whole number, or zero. This condition shall not apply to an instrument of class I with d > 1 mg. In that case e shall uniformly be 1 mg.

The value of e, calculated following this rule, are, for example,

TABLE 42

d =
0.1 g
0.2 g
0.5 g
e =
1 g
1 g
1 g

(a) Example of a complementary indicating device

FIGURE 55-C

(b) Example of indicating devices each with a differentiated scale division

(iv) Minimum capacity

The minimum capacity of the instrument is determined in conformity with the requirements in Table 40.

(v) Minimum number of verification scale intervals

for an instrument of class I with d< 0.1 mg, n may be less than 50 000.

(6) Maximum permissible errors

(i) Values of maximum permissible errors on verification/reverification
The maximum permissible errors allowed for increasing or decreasing loads shall be as given Table 43.

TABLE 43

Maximum permissible errors on verification/ reverification
For loads m expressed in verification scale intervals e
Class I
Class II
Class III
Class IIII
______+ 0.5 e
Min m 50 000
Min m 5000
Min < m 500

Min m 50

______+1 e
50000< m 200 000
5000< m 20 000
500 < m 2000
50 < m 200
______+1.5 e
200000 < m
20000<m 100000
2000 < m 10000
200 < m 1000

(ii) Values of maximum permissible errors in inspection

The maximum permissible errors during inspection shall be twice the maximum permissible errors allowed on verification.

(iii) Basic rules concerning the determination of errors

(a) Influence factors
Errors shall be determined under normal test condition. When the effect of one factor is being evaluated, all other factors are to be kept relatively constant, at a value close to normal.

(b) Maximum permissible errors for net values
The maximum permissible errors apply to the net value of the load for every possible tare load, except preset tare values

(c) Tare weighing device
The maximum permissible error for a tare weighing device are the same, for any tare value as those of the instrument, for the same value of load.

(7) Permissible difference between results

Regardless of what variation of results is permitted, the error of any single weighing result shall by itself not exceed the maximum permissible error for the given load.

(i) Repeatability
The difference between the maximum and minimum results of several weighings of the same load shall not be greater than the absolute value of the maximum permissible error for the given load.

(ii) Eccentric loading
The indications for different positions of a load shall meet the maximum permissible errors, when the instrument is tested according to sub-paragraphs (a) to (d) of this paragraph.

(a) Unless otherwise specified hereafter, a load corresponding to 1/3 of the sum of the maximum capacity and the corresponding maximum additive tare effect shall be applied.

(b) On an instrument with a load receptor having n points of support, with n>4, the fraction 1/(n-1) of the sum of the maximum capacity and the maximum additive tare effect shall be applied to each point of support.

(c) On an instrument with a load receptor subject to minimal off-centre loading (e.g. tank, hopper) a test load corresponding to one-tenth of the sum of the maximum capacity and the maximum additive tare effect shall be applied to each point or support.

(d) On an instrument used for weighing rolling loads (e.g. vehicle scale, rail suspension instrument) a rolling test load corresponding to the usual rolling load, the heaviest and the most concentrated one which may be weighted, but not exceeding 0.8 times the sum of the maximum capacity and the maximum additive tar effect, shall be applied at different points on the load receptor.

(iii) Multiple indicating devices

For a given load the difference between the indications of multiple indicating devices including tare weighing device, shall be not greater than the absolute value of the maximum permissible error, but shall be zero between digital indicating or printing devices.

(iv) Different positions of equilibrium

The difference between two results obtained for the same load when the method of balancing the load is changed (in the case of an instrument fitted with a device for extending the self-indication capacity) in two consecutive tests, shall not exceed the absolute value of the maximum permissible error for the applied load.

(8) Discrimination

(i) Non-self indicating instrument

An extra load equivalent to the value of the maximum permissible error for the applied load when gently placed or withdrawn from the instrument at equilibrium shall produce movement as required under sub-paragraph (1) of paragraph 6.

(ii) Self or semi-self indicating instrument

(a) Analogue indication
An extra load equivalent to the maximum permissible error for applied load when placed gently on or withdrawn from the instrument at equilibrium shall cause a permanent displacement of the indicating element corresponding to not less than 0.7 times the extra load.

(b) Digital indication
An additional load equal to 1.4 times the actual, scale interval, when gently placed on or withdrawn from the instrument at equilibrium shall change the initial indication.

(9) Variation due to influence quantities and time

An instrument shall comply, unless otherwise specified, with sub-paragraphs (6), (7) and (8) of this paragraph under the conditions of (ii) and (iii) of sub-paragraph (9) of this paragraph and additionally it shall comply with clauses (i) and (iv) of sub-paragraph (9) of this paragraph.

(i) Tilting

(a) For instrument of class II, III or IV liable to be tilted, the influence of tilting shall be determined under the effect of a lengthwise or transverse tilting equal to 2/1000 or corresponding to the limiting value of tilting marked on, or indicated by a level indicator, whichever is the greater tilt.

The absolute value of the difference between the indication of the instrument in its reference position (not tilted) and the indication in the tilted position shall not exceed:

—at no load, two verification scale intervals, (the instrument having first been adjusted to zero at no load in its reference position) except instruments of class II.

—at self indication capacity and at maximum capacity, the maximum permissible error (the instrument having been adjusted to zero at no load both in the reference and in the tilted position).

An instrument shall be fitted with a leveling device and a level indicator fixed firmly on the instrument in a place clearly visible to the user, unless the instrument is:

freely suspended, or

installed in a fixed position, or

complying with the requirements on tilting when tilted to 5% in any direction.

The limiting value of the level indicator shall be obvious, so that tilting is easily noticed.

Note: Limiting value of tilting : Displacement of 2 mm from a central position.

(b) On a class I instrument, the limiting value of tilting shall correspond to a tilt of no more than 2/1000 otherwise the instrument shall meet the requirement for instruments of class II.

(ii) Temperature

(a) Prescribed temperature limits

If no particular working temperature is stated in the descriptive markings of an instrument, this instrument shall maintain its metrological properties within the following temperature limits:

–10oC + 40oC

(b) Special temperature limits

An instrument for which particular limits of working temperature are stated in the descriptive markings shall comply with the metrological requirements within those limits.
The limits may be chosen according to the application of the instrument.
The ranges within those limits shall be at least equal to:

5oC for instruments of class (I)

15oC for instruments of class (II)

30oC for instruments of class (III) and (IIII)

(c) Temperature effect on no-load indication

The indication at zero or near zero shall not vary by more than one verification scale interval for a difference in ambient temperature of 1oC for instruments of class (I) and 5oC for other classes.
For multi-interval instruments and for multiple range instruments this applies to the smallest verification scale interval of the instrument.

(iii) Mains power supply

An instrument operated from a mains power supply shall comply with the metrological requirements if the power supply varies:

in voltage from : – 15% to + 10% of the value marked on the instrument,

in frequency : from – 2% to + 2% of the value marked on the instrument, if alternate current is used.

(iv) Time

Under reasonably constant environmental conditions, an instrument of class I, II or III shall meet the following requirements.

(a) When any load is kept on the instrument, the difference between the indication obtained immediately after placing a load and the indication observed during the following 30 minutes, shall not exceed 0.5 e . However, the difference between the indication obtained at 15 minutes and after that at 30 minutes shall not exceed 0.2 e .

If these conditions are not met, the difference between the indication obtained immediately after placing a load on the instrument and the indication observed during the following four hours shall not exceed the absolute value of the maximum permissible error at the load applied.

(b) The deviation on returning to zero as soon as the indication has stabilized, after the removal of any load which has remained on the instrument for one half hour, shall not exceed 0.5 e .

For a multi-interval instrument, the deviation shall not exceed 0.5 e1.

On a multiple range instrument, the deviation on returning to zero from Max1 shall not exceed 0.5 e1. Furthermore, afte returning to zero from any load greater than Max1 and immediately after switching to the lowest weighing range, the indication near zero shall not vary by more than e 1 during the following 5 minutes.

(c) The durability error due to wear and tear shall not be greater than the value of the maximum permissible error.

Adherence to this requirement is assumed if the instrument has passed the endurance test specified in paragraph 9, which shall be performed only for instrument with
Max < 100 kg.

(10) Pattern evaluation tests

Upon pattern evaluation, the tests given in paragraph 9 and Annexure A shall be performed, to verify adherence to the requirement in sub-paragraphs (6), (7) (8) and clauses (i) to (iv) of sub-paragraph (9) of this paragraph, sub-paragraph (5) and (6) of paragraph 4, sub-paragraph (3) of paragraph 5 and sub-paragraph (1) of paragraph 6. The endurance test shall be performed after all other tests in paragraph 9 and Annexure A.

4. Technical requirements for a self or semi-self indicating instruments

(1)  General requirements of construction

(i) Suitability

(a) Suitability for application

An instrument shall be designed to suit its intended purpose of use.

(b) Suitability for use

An instrument shall be solidly and carefully constructed in order to ensure that it maintains its metrological qualities during a period of use.

(c) Suitability for verification

An instrument shall permit the tests set out in this specification to be performed.

In particular, load receptors shall be such that the standard masses can be deposited on them easily and in total safety. If weights cannot be placed, an additional support may be required.

It must be possible to identify devices that have been subject to a separate type examination procedure (e.g. load cells, printers).

(ii) Security

(a) Fraudulent use

An instrument shall have no characteristics likely to facilitate its fraudulent use.

(b) Accidental breakdown and mal-adjustment

An instrument shall be so constructed that an accidental breakdown or a mal-adjustment of control elements likely to disturb its correct functioning cannot take place without its effect being evident.

(c) Controls

Controls shall be so designed that they cannot normally come to rest in positions other than those intended by design, unless during the manoeuvre all indication is made possible, keys shall be marked unambiguously.

(d) Securing (Sealing) of components and pre-set controls

An instrument shall have provisions as required by the director legal metrology, for securing components and preset controls to which access or adjustment likely to affect the metrological characteristics of the instrument, is possible.

On a class I instrument devices to adjust sensitivity may remain unsecured.

(e) Adjustment

If an instrument is fitted with an automatic or a semi-automatic span adjustment device, this device shall be incorporated inside the instrument. External influence upon this device shall be practically impossible after sealing.

(f) Gravity compensation

A gravity sensitive instrument may be equipped with a device for compensating the effects of gravity variation. After securing, external influence on or access to this device shall be practically impossable.

(2) Indication of weighing results

(i) Quality of reading

Reading of the results shall be reliable, easy and unambigu ous under conditions of normal use:

the overall inaccuracy of reading of an analogue indicating device shall not exceed 0.2 e .

the figures forming the results shall be of a size, shape and clarity for reading to be easy.

The scale, numbering and printing shall permit the figures which form the results to be read by simple juxtaposition:

PROVIDED that this requirement shall not be applicable in the case of steel yard type weighing instruments.

(ii) Form of the indication

(a) Weighing results shall contain the names or symbols of the units of mass in which they are expressed.

For any one indication of weight, only one unit of mass shall be used.

The scale interval shall be in the form 1 x 10k, 2 x 10k or 5 x 10k, in which the result is expressed, the index k being a positive or negative whole number or equal to zero.

All indicating, printing and tare weighing devices of an instrument shall, within any one weighing range, have the same scale interval for any given load.

(b) A digital indication shall display at least one figure beginning at the extreme right.

Where the scale interval is changed automatically the decimal sign shall maintain its position in the display.

A decimal fraction shall be separated from its integer by a decimal sign (comma or dot), with the indication showing at least one figure to the left of the sign and all figures to the right.

Zero may be indicated by one zero to the extreme right, without a decimal sign.

The unit of mass shall be chosen so that weight values have not more than one non-significant zero to the right. for values with decimal sign, the non-significant zero is allowed only in the third position after the decimal sign.

(iii) Limits of indication

There shall be no indication above Max + 9 e

(iv) Approximate indication device

The scale interval of an approximate indicating device shall be greater than Max/100 without being smaller than 20 e. This approximate device is considered as giving secondary indications.

(v) Extending the range of self-indication on a semi-self-indicating instrument

The extension interval of the range of self-indication shall not be greater than the value of the self-indication capacity.

(a) The scale interval of extension of the range of the self indication should be equal to the capacity of self, indication (comparator instruments are excluded from this provision).

(b) An extension device with accessible sliding poises is subject to the requirements of clause (ii) of sub-paragraph (2) of paragraph 6.

(c) On an extension device with enclosed sliding poises or mass switching mechanisms each extension should involve an adequate change in the numbering. It should be possible to seal the housing and the adjusting activities of the weights or masses.

(3) Analogue indicating device

The following requirements apply in addition to those in clause (i) to (iv) of sub-paragraph (2) of this paragraph.

(i) Scale marks : Length and width

Scale shall be designed and numbered so that reading the weighing results is easy and unambiguous.

(a) Forms of scale marks.

Scale marks shall consist of lines of equal thickness; this thickness should be constant and between 1/10 and 1/4 of the scale spacing, without being less than 0.2mm. The length of the shortest scale mark should be at least equal to the scale spacing.

(b) Arrangements of scale marks

Scale marks should be arranged in accordance with one of the sketches in Figure 55–D (the line joining the end of the scale marks optional).

(c) Numbering

On one scale, the scale interval of numbering should be:
—constant,

—in the form 1 x 10k, 2 x 10k, 5 x 10k units ( k being a positive or a negative whole number or equal to zero),

—not greater than 25 times as the scale interval of the instrument.

If the scale is projected on a screen, at least two numbered scale marks should appear wholly in the projected zone.

The height of the number (real or apparent) expressed in millimetres should be not less than 3 times the minimum reading distance expressed in metre, without being less than 2 mm.

This height should be proportional to the length of the scale mark to which it relates.

The width of a number, measured parallel to the base of the scale, should be less than the distance between two consecutive numbered scale marks.

(d) Indicating component

The width of the pointer of the indicating components should be approximately equal to that of the scale marks and of the length such that the tip is at least level with the shortest mark.

The distance between the scale and the pointer should be at the most equal to the scale spacing, without being greater than 2 mm.

(ii) Scale spacing

on an instrument of class (I) or (II);

1 mm for indicating devices;

0.25 mm for complementary indicating devices;

on an instrument of class III and IV.

1.25 mm for dial indicating devices.

1.75 mm for optical projection indicating devices.

(iii) Limits of indication

Stops shall be provided to limit the movement of the indicating component whilst allowing it to travel below zero and above the capacity of self-indication. This re-requirements does not apply to multi-revolution dial instruments.

The stops limiting the movement of the indicating components should permit it to travel across zones of at least 4 scale spacings below zero and above the capacity of self-indication (three zones are not provided with a scale on fan charts and on dials with a single revolution pointer they are called “blank zone”).

(iv) Damping

Damping should achieve a stable indication within 5 simple half periods of oscillation.

Hydraulic damping elements sensitive to variations in temperature should be provided with an automotive regulating device or an easily accessible manual regulating device.

It should be impossible for the fluid of hydraulic damping elements on portable instruments to spill when the instrument is inclined at 45o.

(4) Digital indicating and printing devices

The following requirements apply in addition to those in clauses (i) to (v) of sub-paragraph (2) of this paragraph.

(i) Change of indication

After a change in load, the previous indication shall not persist for longer than 1 second.

(ii) Stable equilibrium

Equilibrium is deemed to be stable when,—

in case of printing and/or data storage, the requirement in clause (v) of sub-paragraph (4) of this paragraph are met,

in case of zero or tare operations clauses (iv), (vi), (vii) of sub-paragraph (5) and (viii) of sub-paragraph (6) of this paragraph, it is sufficiently close to the final equilibrium to allow a correct operation of the device within relevant accuracy requirements.

(iii) Extended indicating device

An extended indicating device shall not be used on an instrument with a differentiated scale division.

When an instrument is fitted with an extended indicating device, displaying the indication with a scale interval smaller than ‘e' shall be possible only.

during pressing a key, or

for a period not exceeding 5 seconds after a manual command.

In any case printing shall not be possible.

(iv) Multiple use of indicating device

Indications other than primary indication may be displayed in the same indicting device, provided that,—

Quantities other than weight values are identified by the appropriate unit of measurement, or symbol thereof, or a special sign.

Weight values that are not weighing results (sub-clause (i) through clause (iii) of sub-paragraph (2) of paragraph 5 Part I ) shall be clearly identified, or they may be displayed only temporarily on manual command and shall not be printed.

No restrictions apply if the weighing mode is made inoperative by a special command.

(v) Printing device

Printing shall be clear and permanent for the intended use, printed figures shall be at least 2 mm high.

If printing takes place, the name or the symbol of the unit of measurement shall be either to the right of the value or above a column of values.

Printing shall be impossible when the equilibrium is not stable.

Stable equilibrium is considered to be achieved when over a period of 5 seconds following printout, no more than two adjacent values are indicated, one of which being the printed value.

(vi) Memory storage device

The storage of primary indications for subsequent indication, date transfer, totalizing, etc, shall be impossible when the equilibrium is not stable. The criterion of stable equilibrium is the same as in clause (v) of sub-paragraph (4) of paragraph 4.

(5) Zero setting and zero-tracking devices

An instrument may have one or more zero-setting devices and shall have not more than one zero-tracking device.

(i) Maximum effect

The effect of any zero setting device shall not alter the maximum weighing capacity of the instrument.

The overall effect of zero setting and zero tracking device shall be not more than 4% and of the initial zero setting device not more than 20% of the maximum capacity.

(ii) Accuracy

After zero setting, the effect of zero deviation on the result of the weighing shall be not more than 0.25 e; however, on an instrument with auxiliary indicating device this effect shall be not more than 0.5 d.

(iii) Multiple range instrument

Zero setting in any weighing range shall be effective also in the greater weighing ranges if switching to a greater weighing range is possible while the instrument is loaded.

(iv) Control of the zero setting device

An instrument except an instrument according to sub-paras (13) and (14) of this paragraph,

whether or not equipped with an initial zero-setting device, may have a combined semi-automatic zero-setting device and a semi-automatic tare-balancing device operated by the same key.

If an instrument has a zero device and a tare-weighing device, the control of the zero-setting device shall be separated from that of the tare-weighing device.

A semi-automatic zero setting device shall function only; and when the instrument is in stable equilibrium, it cancels any previous tare operation.

(v) Zero indicating device on an instrument with digital indication

An instrument with digital indication shall have device that displays a special signal when the deviation from zero is not more than 0.25 e. This device may also work when zero is indicated after a tare operation.

This device is not mandatory on an instrument that has an auxiliary indicating or a zero-tracking device provided that the rate of zero tracking is not less than 0.25 d/second.

(vi) Automatic zero setting device

An automatic zero-setting device shall operate only when,—

the equilibrium is stable, and

the indication has remained stable below zero at least 5 seconds.

(vii) Zero tracking device

A zero tracking device shall operate only when,—

the indication is at zero, or at a negative net value equivalent to gross zero, and

the equilibrium is stable, and

the corrections are not more than 0.5 d/second.

When zero is indicated after a tare operation, the zero tracking device may operate within a range of 4% of max around the actual zero value.

(6) Tare device

(i) General requirements :

A tare device shall comply with the relevant provisions of sub-paragraph (1) through (4) of this paragraph.

(ii) Scale interval :

The scale interval of a tare-weighing device shall be equal to the scale interval of the instrument for any given load.

(iii) Accuracy :

A tare device shall permit setting the indication to zero with an accuracy better than:

+ 0.25e for electronic instruments and any instrument with analogue indication.

+ 0.25e for mechanical instruments with digital indication and instruments with auxiliary indication device.

On a multi-interval instrument e shall be replaced by e1.

(iv) Operating range

The tare device shall be such that it cannot be used at or below its zero effect or above its maximum indicated effect.

(v) Visibility of operation

Operation of the tare device shall be visibly indicated on the instrument. In the case of instruments with digital indication this shall be done by marking the indicated net value with the sign “NET” or “Net” or “net”.

Note: If an instrument is equipped with a device that allows the gross values to be displayed temporarily while a tare device is in operation, the “NET” symbol disappears while the gross value is displayed.

This is not required for an instrument with a combined semiautomatic zero-setting device and a semi-automatic tare-balancing device operated by the same key.

(vi) Subtractive tare device :

When the use of subtractive tare device does not allow the value of the residual weighing range to be known, a device shall prevent the use of the instrument above its maximum capacity or indicate that this capacity has been reached.

(vii) Multiple range instrument :

On a multiple range instrument the tare operation shall be effective also in the greater weighing ranges, if switching to a greater weighing range is possible while the instrument is loaded.

(viii) Semi-automatic or automatic tare devices

These devices shall operate only when the instrument is in stable equilibrium.

(ix) Combined zero setting and tare balancing device

If the semi automatic zero setting device and semi automatic tare balancing device are operated by the same key; sub clause (ii) and (v) of sub-paragraph (5) of this paragraph and if appropriate sub-clause (vii) of sub-paragraph (5) of this paragraph apply at any load.

(x) Consecutive tare operations

Repeat operation of a tare device is permitted.

If more than one tare device is operative at the same time, tare weight values shall be clearly designated when indicated or printed.

(xi) Printing of weighing results

Gross weight values may be printed without any designation. For a designation by a symbol, only “G” is permitted.

If only net weight values are printed without corresponding gross or tare values, they may be printed without any designation. A symbol for designation shall be “N”. This applies also where semi-automatic zero setting and semi-automatic tare balancing are initiated by the same key.

Gross, net or tare values determined by a multiple range instrument or by a multi-interval instrument need not be marked by a special designation referring to the (partial) weighing range.

If net weight values are printed together with the corresponding gross and/or tare values, the net and tare values shall at least be identified by the corresponding symbol “N” and “T”.

However, it is permitted to replace the symbols G, N, T by complete words.

If net weight values and tare values determined by different tare devices are printed separately, they shall be suitably identified.

(7) Preset tare device

(7)(i) Scale interval

Regardless of how a preset tare value is introduced into the device, its scale interval shall be equal or automatically rounded to the scale interval of the instrument. On a multiple range instrument, a preset tare value may only be transferred from one weighing range to another one with a larger verification scale interval but shall then be rounded to the latter. For a multiple interval instrument, the maximum preset tare value shall not be greater than Max 1 and the indicated or printed, calculated net value shall be rounded to the scale interval of the instrument for the same net weight value.

(ii) Modes of operation

A preset tare device may be operated together with one or more tare devices provided that:

clause (x) of sub-paragraph (6) of this paragraph is complied, and

a Preset tare operation cannot be modified or cancelled as long as any tare device operated after the preset tare operation is still in use.

preset tare devices may operate automatically only if the preset tare value is clearly identified with the load to be measured.

(iii) Indication of operation

For the indicating device clause (v) of sub-paragraph (6) of this paragraph applies. It shall be possible to indicate the preset tare value at least temporarily.

Provisions of clause (xi) of sub-paragraph (6) of paragraph 4 applies accordingly provided that

if the calculated net value is printed, at least the preset tare value is printed as well, with the exception of an instrument covered by sub-paragraphs (13), (14) or (16) of this paragraph.

Preset tare values are designated by the symbol “PT”; however, it is permitted to replace the symbol “PT” by complete words.

(8) Locking positions

(i) Prevention of weighing outside the “weight” position

If an instrument has one or more locking device, these devices shall only have two stable positions corresponding to “locked” and “weigh”; and weighing shall only be possible in the “weigh” position.

A “pre-weigh” position may exist on any instrument of class I or II, except under sub-paragraphs (13), (15) or (16) of this paragraph.

(ii) Indication of position

The “locked” and “weigh” positions shall be clearly shown.

(9) Auxiliary calibration devices (removable or fixed)

(i) Devices with one or more platform

The nominal value of the ratio between the weights to be placed on the platform to balance a certain load and this load shall not be less than 1/5000 (it shall be visibly indicated just above the platform).

The value of the weights needed to balance a load equal to the verification scale interval shall be an integer multiple of 0.1g

(ii) Numbered scale devices

The scale interval of the auxiliary verification devices shall be equal to or smaller than 1/5 of the verification scale interval for which it is intended.

(10) Selection of weighing ranges on a weighing scale on a multiple range instrument

The range which is actually in operation shall be clearly indicated.

(a) Manual selection of the weighing range is allowed

—from a smaller to a greater weighing range at any load;

—from a greater to a smaller weighing range when there is no load on the load receptor and the indication is zero at a negative net value. The tare operation receptor shall be cancelled and the zero shall be set to + 0.25 e both automatically.

(11) Device for selection (or switching) between various load receptors—Load transmitting devices and various load measuring devices

(i) Compensation of no load effect

The selection device shall ensure compensation for the unequal no load effect of the various load receptors-load transmitting devices, in use.

(ii) Zero setting

Zero setting of an instrument with any multiple combination of various load measuring devices and various load receptors shall be possible without any ambiguity and in accordance with the provisions of sub-paragraph (5) of paragraph 4.

(iii) Impossibility of weighing

Weighing shall not be possible while selection devices are being used.

(iv) Identification of the combination use

Combination of load receptors and load measuring devices used shall be readily identifiable.

(12) “Plus” and “minus” comparative instrument

For the purpose of verification a “heavy” or “plus” and “light” or minus” comparators instrument is considered to be a semi-self indicating instrument.

(i) Distinction between “plus” and “minus” zone

On an analogue indicating device, the zones situated on either side of zero shall be distinguished by “+” and “-”.

On a digital indicating device, an inscription nearer the indicating device shall be given.

range ± .......... gram (kg,t)

range ...........gram (kg,t)/+......gram (kg,t)

(ii) Form of scale

Scale of a comparator instrument shall have at least one scale division d equal to e (d = e) on either side of zero. The corresponding value shall be shown at either end of the scale.

(13) Additional requirement for an instrument for direct sales to the publi c

The following requirements apply to an instrument of class II, III, or IV with a maximum capacity not more than 100 kg capacity designed for direct sale to the public.

(i) Primary indication

On an instrument for direct sale to the public, the primary indications are the weighing results and the information about the correct zero position, tare, and pre-set tare operation.

(ii) Zero setting device

An instrument for direct sale to the public shall not be fitted with a non-automatic zero setting device unless operated with a tool.

(iii) Tare device

A mechanical instrument with a weight receptor shall not be fitted with a tare device.

An instrument shall not be fitted with a device which can recall the gross value while a tare or pre-set tare device is in operation.

(a) Non-automatic tare device

A displacement of 5 mm of a point of the control shall be at the most equal to one verification scale interval.

(b) Semi-automatic tare device

An instrument may be fitted with semi automatic tare device if—

the action of the tare device does not permit the reduction of the tare; and

their effect can only be cancelled when there is no load on the load receptor.

In addition, the instrument shall comply with at least one of the following requirements :

the tare value is indicated permanently in a separate display,

the tare value is indicated with a sign “-” (minus), when there is no load on the load receptor, or

the effect of the device is canceled automatically when the indication returns to zero when unloading the load receptor after the stable net weighing results greater than zero has been indicated.

(c) Automatic tare device

An instrument shall not be fitted with an automatic tare devices.

(iv) Preset tare device

A preset tare device may be provided if the preset tare value is indicated as a primary indication on a separate display which is clearly differentiated from the weight display sub-clause (b) of clause (iii) of sub-paragraph (13) of this paragraph, applies.

It shall not be possible to operate a pre-set tare device, if a tare device is in use.

Where a preset tare is associated with a price look up (PLU), the preset tare value may be cancelled at the same time, as the PLU is cancelled.

(v) Impossibility of weighing

It shall be impossible to weigh or to guide the indicating element during the normal locking operation or during the normal operation of adding or subtracting weights.

(vi) Visibility

All primary indications shall be displayed clearly and simultaneously to both the vendor and the customer.

On digital devices that display primary indications, the numerical figures on either set shall be of the same dimension and at least 10 mm high, with a tolerance of 0.5 mm

On an instrument to be used with weights, it shall be, possible to distinguish the value of the weights.

(vii) No auxiliary and extended indicating device

An instrument shall not be fitted with any auxiliary indicating device nor an extended indicating device.

(viii) Instrument of class II

An instrument of class II shall comply with the requirements given in sub-paragraph (9) of paragraph 3 for an instrument of class III.

(ix) Significant fault

When a significant fault has been detected, a visible or audible alarm shall be provided for the customer, and data transmission to any peripheral equipment shall be prevented. This alarm shall continue until such time as the user takes action or the cause disappears.

(x) Counting ratio

The counting ratio on a mechanical counting instrument shall be 1/10 or 1/100.

(14) Additional requirements for an instrument for direct sale to the public with price indication

The following requirements are to be applied in addition to sub-para (13) of this rule.

(i) Primary indications

On a price indicating instrument, the supplementary primary indication are unit price and price to pay and if applicable, number, unit price and price to pay for non-weighed articles and price totals. Price charts, such as fan charts, are not subject to the requirements of this specification.

(ii) Instrument with price scales

For unit price and price-to-pay scales, sub-paragraph (2) of this paragraph and clause (i) to (iii) of sub-paragraph (3) of this paragraph apply accordingly. The decimal shall be indicated to two places.

Reading from price scales shall be so possible that the absolute value of the difference between the product of the indicated weight W and unit price U and the indicated price to pay P is not greater than the product of e and the unit price of that scale.

|W. U – P | < e. U

(iii) Price computing instrument

(a) The price to pay shall be calculated and rounded to the nearest interval of price to pay, by multiplication of weight and unit price, both as indicated by the instrument. The device which performs the calculations in any case considered a part of the instrument.

(b) The unit price is restricted to price/100g or price/kg.

(c) Notwithstanding the provisions in clause (i) of sub-paragraph (4) of this paragraph, the indication of weight unit price and price to pay, shall remain visible after the weight indication is stable and after any introduction of the unit price, for at least one second and while the load is on the load receptor.

(d) Notwithstanding the provisions in clause (i) of sub-paragraph (4) of this paragraph, these indications may remain visible for not more than 3 seconds after removing the load, provided that the weight indication has been stable before and the indication would otherwise be zero. As long as there is a weight indication after removing the load, it shall not be possible to introduce or change a unit price.

(e) If transaction performed by the instrument are printed, weight, unit price and price-to-pay shall all be printed.

(f) The data may be stored in a memory of the instrument before printing. The same data shall not be printed twice on the ticket for the customer.

Instrument that can be used for price labeling purpose, must comply with sub-paragraph (16) of this paragraph as well.

(iv) Special applications of a price computing instrument

Only if all transaction performed by the instrument or by connected peripheral are printed on a ticket or label intended for the customer, a price computing instrument may perform additional functions which facilitate trade and management. These functions shall not lead to confusion about the results of weighing and price computing.

Other operations or indications not covered by the following provisions may be performed, provided that no indication which could possibly be misunderstood as a primary indication, is presented to the customer.

(a) Non-weighed articles

An instrument may accept and record positive or negative prices to pay one of several non-weighed articles, provided the weight indication is zero or the weighing mode is made inoperative. The price-to-pay for one or more of such articles, shall be shown in the price-to-pay display.

If the price to pay is calculated for more than one equal article, the number of such articles shall be shown on the weight display, without being possibly taken for a weight and the price for one article on the unit price display, unless supplementary display are used to show the number of articles and articles price.

(b) Totalisation

An instrument may totalize transaction on one or several tickets; the price total shall be indicated on the price-to-pay display and printed, accompanied by a special word or symbol, either at the end of the price-to-pay column or on a separate label ticket with appropriate reference to the commodities whose prices to pay have been totalised; all prices to pay that are totalized shall be printed and the price total shall be the algebraic sum of all these prices as printed.

An instrument may totalize transaction performed on other instruments linked to it, directly or over metrologically controlled peripherals, and if the price-to-pay scale intervals of all connected instruments are identical.

(c) Multi-vendor operation

An instrument may be designed to be used by more than one vendor or to serve more than one customer at the same time provided that the connection between the transactions and the relevant vendor or customer is appropriately identified.

(d) Cancellation

An instrument may cancel previous transaction, where the transaction has already been printed, the relevant price-to-pay cancelled shall be printed with an appropriate comment. If the transaction to the cancelled is displayed to the customer, it shall be clearly differentiated from normal transaction.

(e) Additional information

An instrument may print additional information if this is clearly corelated to the transaction and does not interfere with the assignment of the weight value to the unit symbol.

(v) Self service instrument

A self service instrument need not have two sets of scales displayed.

If a ticket or label is printed, the primary indications shall include a designation of the product when the instrument used to sell different products.

(15) Instruments similar to one normally used for direct sale to the public

An instrument similar to one normally used for direct sale to the public which does not comply with the provisions of sub-paragraphs (13) and (14) of this paragraph shall carry near the display, the indelible marking:

“NOT TO BE USED FOR DIRECT SALE TO THE PUBLIC”

(16) Price labelling instrument

Clause (viii) of sub-paragraph (13), sub-clause (a) and (e) of clause (iii) of sub-paragraph (14), sub-clause (a) of clause (iv) of sub-paragraph (14) and sub-clause (e) of clause (iv) of sub-paragraph (14) of this paragraph respectively apply.

A price labelling instrument shall have at least one display for the weight. it may be used temporarily for set-up purpose such as supervision of setting weight limits, unit price, preset tare values, commodity names.

It shall be possible to verify, during use of the instruments, the actual values of unit price and preset tare value.

Printing below minimum capacity shall not be possible.

Printing of labels with fixed values of weight, unit price and price-to-pay is allowed provided that the weighing mode is made in-operative.

(17) Mechanical counting instrument with unit-weight receptor

For the purpose of verification, a counting instrument is considered to be a semi-self indicating instrument.

(i) Indicating device

To permit verification, a counting instrument shall have a scale with at least one scale division d = e on either side of zero, the corresponding value shall be shown on the scale.

(ii) Counting ratio

The counting ratio shall be shown clearly just above each counting platform or each counting scale mark.

5. Requirements for electronic instruments

In addition to paragraphs 3 and 4, an electronic instrument shall comply with the following requirements.

(1)  General requirements

(i) An electronic instrument shall be designed and manufactured such that when it is exposed to disturbances:

either;

(a) significant faults do not occur, or

(b) significant faults are detected and acted upon.

Note: A fault equal to or smaller than e is allowed irrespective of the value of the error of indication.

(ii) The requirements in sub-paragraphs (6), (7), (8) and (9) of paragraph 3 and clause (i) of sub-paragraph (1) of this paragraph shall be met durably in accordance with the intended use of the instrument.

(iii) A pattern of an electronic instrument is presumed to comply with the requirements in clause (i) and (ii) of sub-paragraph (1) and clause (ii) of sub-paragraph (3) of this paragraph, if it passes the examinations and tests specified in sub-paragraph (4) of this paragraph.

(iv) The requirements in (i) of sub-paragraph (1) of this paragraph may be applied separately to

(a) each individual clause of significant fault, and/or

(b) each part of the electronic instrument

The choice, where sub-clause (a) or (b) of clause (i) of sub-paragraph (1) of paragraph 5 is applied, is left to the manufacturer.

(2) Acting upon significant faults

When a significant fault has been detected, the instrument shall either be made inoperative automatically or a visual or audible indication shall be provided automatically and shall continue until such time as the user takes action or the fault disappears.

(3) Functional requirements

(i) Upon switch on (switch-on of indication), a special procedure shall be performed that shows all relevant signs of the indicator in the active and non-active state sufficiently long to be checked by the operator.

(ii) In addition to the sub-paragraph (9) of paragraph 3 an electronic instrument shall comply with the requirements under relative humidity of 85% at the upper limit of the temperature range. This is not applicable to an electronic instrument of class I and of class II, if e is less than 1 g .

(iii) Electronic instruments, class I instruments exempted, shall be subjected to the span stability test specified in clause (iv) of sub-paragraph (4) of this paragraph. The error near maximum capability shall not exceed the maximum permissible error and the absolute value of the difference between the errors obtained for any two measurements shall not exceed half the verification scale interval or half the value of the maximum permissible error, whichever is greater.

(iv) When an electronic instrument is subjected to the disturbances specified in clause (iii) of sub-paragraph (4) of this paragraph, the difference between the weight indication without the disturbance (intrinsic error), shall not exceed e or the instruments shall detect and react to a significant fault.

(v) During the warmup time of an electronic instrument there shall be no indication or transmission of the weighing result.

(vi) An electronic instrument may be equipped with interfaces permitting the coupling of the instrument to any peripheral devices or other instruments.

An interface shall not allow the metrological functions of the instruments measurement data to be inadmissibly influenced by the peripheral devices (for example computers), by other interconnected instruments, or by disturbances acting on the interface.

Functions that are performed or initiated via an interface shall meet the relevant requirements and conditions of clause (iv) of this sub-paragraph.

Note : An “interface” comprises all mechanical, electrical and logic properties at the data interchange point between an instrument and peripheral devices or other instruments.

(a) It shall not be possible to introduce into an instrument, through an interface, instructions or data intended or suitable to:

- display data that are not clearly defined and could be mistaken for a weighing result,

- falsify displayed, processed or stored weighing results,

- adjust the instrument or change any adjustment factor; however instructions may be given through the interface to carryout an adjustment procedure using a span adjustment device incorporated inside the instrument or for instruments in class I, using an external standard mass,

- falsify primary indication displayed in case of direct sales to the public.

(b) An interface through the functions mentioned in sub-clause (a) of clause (vi) of sub-paragraph (3) of this paragraph cannot be performed or initiated, need not be secured. Other interface shall be secured as per sub-clause (d) of clause (ii) of the sub-paragraph (1) of paragraph 4.

(c) An interface intended to be connected to a peripheral device to which the requirements of this (Schedule) apply, shall transmit data relating to primary indication in such a manner that the peripheral device can meet the requirements.

(vii) A battery operated electronic instrument shall either continue to function correctly or not indicate any weight values, whenever the voltage is below the manufacturer's specified value.

(4) Performance and span stability tests

(i) Test considerations :

All electronic instruments of the same category, whether or not equipped with checking facilities, shall be subjected to the same performance test programme.

(ii) State of instrument under test :

Performance tests shall be carried out on fully operational equipment in its normal operational state or in a status, as similar as possible thereto.

If an electronic instrument is equipped with an interface permitting the coupling of the instrument to external equipment, the instrument shall, during the tests mentioned in sub-paragraphs (2), (3) and (4) of paragraph 3 of Annexure A be coupled to external equipment, as specified by the test procedure.

(iii) Performance test

Performance tests shall be performed according to paragraphs 2 and 3 of Annexure A.

TABLE 43-A

Tests
Characteristic under test
Characteristic under test
Influence factor
Damp heat, steady state
Influence factor
Power voltage variations
Influence factor
Short time power reductions
Disturbance
Bursts (transients)
Disturbance
Electrostatic discharge
Disturbance
Electromagnetic susceptibility
Disturbance

(iv) Span stability test

Span stability test shall be performed according to paragraph 4 of Annexure A.

6. Technical requirements for a non-self indicating instrument

A non-self-indicating instrument shall comply, as far as applicable, with paragraphs 3 and 4.

(1) Minimum sensitivity

An extra load equivalent to the absolute value of the maximum permissible error for the applied load, shall be placed on the instrument at equilibrium and shall cause a permanent displacement of the indicating element of at least

1 mm for an instrument of class I or II

2 mm for an instrument of class III or IV with Max 30 kg

5 mm for an instrument of class III or IV with Max 30 kg

The sensitivity tests shall be carried out by placing extra loads with a slight impact in order to eliminate the effects of discrimination threshold.

(2) Indicating device

(i) General provisions

          (a) Equilibrium indicating component

If two indices are provided, with one fixed and another movable then the thickness of the two indicating components shall be equal and the distance between them shall not exceed their thickness.

However, this distance may be equal to 1 mm, if the thickness of the indices is less than this value.

(b) Securing

It shall be possible to secure the sliding poises, the removable masses and the adjusting cavities or the housings of such devices as prescribed by Director.

(c) Printing

If the device permits printing, this should be possible only if sliding bars or poises or a mass switching mechanism are each in a position corresponding to a whole number of scale divisions. Except for accessible sliding poises or bars, printing should be possible only if the equilibrium indicating component is in the reference position to within the nearest half scale interval.

(ii) Sliding poise device

(a) Form of scale marks

On bars on which the scale interval is the verification scale interval of the instrument, the scale marks shall consists of lines of constant thickness. On other major (or minor) bars, the scale marks shall consist of notches.

(b) Scale spacing

The distance between scale marks shall not be less than 2 mm and be of sufficient length so that the normal machining tolerance for notches or scale marks do not cause an error in the weighing result exceeding 0.2 of the verification scale interval.

(c) Stops

The displacement of sliding poises on major and minor bars shall be limited to the graduated part of major and minor bars.

(d) Indicating component

Each sliding poise device shall be provided with an indicating component.

(e) Accessible sliding poise device

There shall be no moving parts in sliding poises, except sliding minor bars.

There shall be no cavity on sliding poises that could accidentally hold foreign bodies.

It shall be possible to secure parts that are detachable.

The displacement of sliding poises on major and minor bars shall require a certain effort.

(iii) Indication by use of proportional weights

The reduction ratios shall be in the form 10 k , k being an integer or zero.

On an instrument intended for direct sale to the public, the height of the raised edge of the weights receptor platform should not exceed one tenth of the greatest dimension of the platform, without being more than 25 mm.

(3) Condition of construction

(i) Equilibrium indicating component

An instrument shall be provided with two moving indices or one moving indicating component and a fixed datum mark, the respective position of which indicates the reference position of equilibrium.

On an instrument of class III or IV designed to be used for direct sale to the public, the indices shall allow the equilibrium to be seen from the opposite sides of the instrument.

(ii) Knives, bearings and friction plates.

(a) Types of connection

Levers shall be fitted with knives only and these shall be pivoted on bearings.

The line of contact of the knives and bearing shall be a straight line.

Counter beams shall be pivoted on knife edges.

(b) Knives

The knives shall be fitted to the levers in such a way that the invariability of the ratios of the lever arms is assured. They shall not be welded or soldered.

The edges of the knives of one and the same lever shall be practically parallel and shall be situated in one plane.

(c) Bearings :

The bearings shall not be welded or soldered to their supports or intheir mountings.

It shall be possible for bearings of an instrument with ratio platforms and steelyards to oscillate in all directions on their supports or in their mountings. On such instruments anti-disconnection devices shall prevent the disconnection of articulated parts.

(d) Friction plates :

The longitudinal play of the knives shall be limited by friction plates. There shall be point contact between knife and friction plates and it shall be situated on the extension of the line(s) of contact between knife and bearing(s).

The friction plate shall form a plane through the point of contact with the knife and its plane shall be perpendicular to the line of the contact between knife and bearing. It shall not be welded or soldered to the bearings or their support.

(iii) Hardness

Contact parts of knives, bearings, friction plates, inter levers, inter lever supports and links shall have a hardness of at least 58 Rockwell C.

(iv) Protective coating

A protective coating may be applied to the parts in contact of jointed components provided that this does not lead to changes of metrological properties.

(v) Tare devices

No instrument shall be fitted with a tare device.

(4) Simple sliding poise instrument (steelyard)

(i) General

(a) Scale marks : The scale marks shall be lines or notches, either on the edge, or on the flat of the graduated shank.

The minimum scale spacing is 2 mm between notches and 4 mm between lines.

(b) Pivots : The load per unit length on the knives shall be not more than 10 kg/mm.

The bores of bearing in the form of an annulus shall have a diameter at least equal to 1.5 times the largest dimension of the cross section of the knife.

(c) Equilibrium indicating component

The length of the equilibrium indicating component, if provided taken from the edge of the fulcrum knife-edge of the instrument, shall be not less than 1/15 of the length of the graduated part of the major sliding poise bar.

(d) Distinctive mark

The head and the sliding poise of an instrument with detachable sliding poises shall bear the same distinctive mark.

(ii) Instrument with single capacity

(a) Minimum distance between knife-edges

The minimum distance between knife-edges is,—

25 mm for maximum capacities less than or equal to 30 kg.

20 mm for maximum capacities exceeding 30 kg.

(b) Graduation

The graduation shall extend from zero to the maximum capacity.

(c) Zero setting

If an instrument of class III or IV is provided with a zero-setting device, this shall be a captive screw or nut arrangement with a maximum effect of 4 verification scale intervals per revolution.

(5) Instrument with a load measuring device with accessible sliding poises (of steelyard type)

(i) General

The provisions of sub-paragraph (2) of paragraph 6 relating to load measuring devices with accessible sliding poises shall be observed.

(ii) Range of numbered scale

The numbered scale of the instrument shall permit continuous weighing from zero to the maximum capacity.

(iii) Minimum scale spacing

The scale spacing ix of the different bars (x = 1, 2, 3....)

ix> dx/(e x 0.05) mm but ix> 2mm

(iv) Ratio platform

If an instrument is provided with a ratio platform for extending the indicating range of the numbered scale, the ratio between the value of the weights placed on the platform to balance a load and the load itself shall be 1/10 or 1/100.

This ratio shall be indicated legibly and permanently on the beam in a position close to the ratio platform, in the form 1 : 10, 1 : 100 or 1/10, 1/100.

(v) Zero setting

An instrument shall have a zero-setting device consisting:

either of a cup with greatly convex cover

or of a captive screw or nut arrangement with a maximum effect of 4 verification scale intervals per revolution.

(vi) Locking of the beam

An instrument shall have a manual device for locking the beam, the action of which prevents the equilibrium indices coinciding when at rest.

(vii) Wooden parts

If certain parts of an instrument, such as the frame, the platform or the board are of wood, this shall be dry and free from defects. It shall be covered with a paint or an effective protective varnish.

No nails shall be used for the final assembly of wooden parts.

7. Marking of an instrument

(1) Descriptive markings

All instruments shall carry, in order, the following markings :

(i)
Compulsory in all cases

- manufacturer's mark, or name written in full, indication of accuracy class in the form

for special accuracy
I
for high accuracy
II
for medium accuracy
III
for ordinary accuracy
IIII
- maximum capacity in the form
Max
- minimum capacity in the form
Min
- verification scale interval in the form
e=
(ii)
Compulsory if applicable
- mark of manufacturer's agent for an imported instrument,
- identification mark on each unit of an instrument consisting of separate but associated units.
- pattern approval mark,
- scale interval if < e
in the form d =
- maximum additional tare effect
in the form T = +...
- maximum subtractive tare effect if different from Max
in the form T = – ...
- maximum safe load
in the form Lim =
- the special temperature limits within which the instrument complies with
the prescribed conditions of correct
operation in the form
oC/ ....... oC/
- counting ratio on a counting instrument -in the form
1 : ...... or 1/........
- range of plus/minus indication of a digital comparator instrument in the form
+........mg/g/kg/t

(iii) Presentation of descriptive markings

The descriptive marking shall be indelible and of a size shape and clarity allowing easy reading.

They shall be grouped together in a clearly visible place either on a descriptive plate fixed to an instrument, or on a part of the instrument itself.

The markings:

Max..............

Min.............

e.................

d if d = e and

Accuracy class.......

shall also be shown near the display of the result if they are not already located there.

It shall be possible to seal the plate bearing the descriptive marking.

(a) Markings in special cases :

In special case, some of the markings shall be in the form of a table as illustrated below:—

For a multi-interval instrument
For an instrument with more than one weighing range (W1, W2)
For an instrument with weighing ranges in different classes
W1
W2
W1
W2
II
III
Max 2/5/15 kg
Max 20 kg
100 kg
Max 1000 g
5000 g
Min 20 g
Min 200g
1 kg
Min 5 g
40 g
e = 1/2/5 g
e = 10 g
50 g
e = 0.1 g
2 g
e = 0.02 g
2 g

(b) Dimensions :

When several plates are placed one above the other (as for example in the case of an instrument consisting of several separate devices) they should be of the same width. This common width is fixed at 80 mm.

(c) Fixing :

The plate shall be fixed by rivets or screws with one of the rivets of red copper or material having qualities recognised as similar. It should be possible to secure the head of one of the screws by means of a lead cap inserted in a device that cannot be dismantled. The diameter of the rivet or of the lead cap should be able to accommodate a stamp 4 mm in diameter.

(d) Dimension of the letters : The height of capital letters should be at least 2 mm.

(iv) Specific cases

(a) Instrument having several load receptors and load measuring devices

Each load measuring device which is connected or can be connected to one or more load receptors, shall bear the descriptive markings relating to these viz.

identification mark,

maximum capacity,

minimum capacity,

verification scale interval and

if appropriate, maximum safe load and maximum additive tare effect.

(b) Instruments consisting of separately built main parts

If main parts cannot be exchanged without altering the metrological characteristics of the instrument, each unit shall have an identification mark which shall be repeated in the descriptive markings.

(2) Verification marks

(i) Position

An instrument shall have a place for the application of verification marks.

This place shall,—

be such that the part on which it is located cannot be removed from the instrument without damaging the marks

allow easy application of the marks without changing the metrological qualities of the instrument

be visible without the instrument having to be moved, when it is in service.

(ii) Mounting

An instrument required to bear verification marks shall have a verification mark support, at the place provided for above, which ensures the conservation of the marks:

(a) When the mark is of the self-adhesive type, a space shall be provided on the instrument for the application of the mark.

8. Metrological control

(1) Verification

(i) Visual inspection

Before testing, the instrument shall be visually inspected for

metrological characteristics, i.e., accuracy class, Min, Max e, d.

prescribed inscription and position for verification and control marks.

model approval number wherever applicable.

(ii) Tests

Tests shall be carried out to verify compliance with the following requirements:

- clause (i) of sub-para (6) of paragraph 3—Value of maximum permissible error,

- sub-clauses (b) and (c) of clause (iii) of sub-paragraph (6) of paragraph 3—Maximum permissible error for net and tare values,

- clause (ii) of sub-paragraph (6) of paragraph 3—Scale interval of the tare weighing device,

- clause (iii) of sub-paragraph (7) of paragraph 4 operation of the tare device shall be visible.

- clause (i) of sub-paragraph (7) of paragraph 3 repeatability (3 weighing on classes III and IIII and 6 weighing for I and II)

- clause (ii) of sub-paragraph (7) of paragraph 3-Eccentric loading

- sub-paragraph (8) of paragraph 3—Discrimination

(iii) Stamping

Verification shall be testified by verification marks. All components whose dismantling or maladjustment might alter the metrological characteristics of the instrument should be secured by a seal.

(2) Inspection

During inspection the following tests shall be carried

- maximum permissible error; clause (i) of sub-paragraph (6) of paragraph 3,

- Eccentric loading; clause (ii) of sub-paragraph (7) of paragraph 3,

- the seal applied during verification shall remain intact.

9. Test procedure during verification and inspection

9(1) Evaluation of error

At a certain load L, the indicated value, I is noted. Additional weights of say 1/10 e are successively added until the indication of the instrument is increased unambiguously by one scale interval (I + e). The additional load DL added to the load receptor gives the indication P, by using the formula

P = I + (1/2e) – L

The error is E = P-L

= I + (1/2e) – L – L

< mpe

(2) Weights

(i) The standard weights used for verification of an instrument shall not have an error greater than 1/3 of the maximum permissible error of the instrument for the applied load.

(ii) Substitution of standard weights : While verifying instrument with maximum of 1 tonne and more, instead of standard weights, any other constant load may be used, provided that standard weights of at least 1 tonne or 50% of maximum, whichever is greater, is used.

(3) Weighing tests

Apply test loads from zero up to and including Max. and similarly remove the test loads back to zero. During verification 5 test loads shall be selected and during inspection 3 test loads.

The test loads selected shall include Max., Min and values at or near those at which the maximum permissible error changes. When loading or unloading, the weights shall be progressively increased or decreased. If the instrument is provided with an automatic zero setting device, it shall remain in operation during test. Error is calculated as given in sub-para (1) above.

(4) Weighing test using substitution method

Apply the test loads from zero up to and including maximum portion of the standard weights. Determine the error and then remove the weights so that the no load indication, or in the case of an instrument with a zero tracking device, the indication of say 10e, is reached.

Substitute the previous weights with substitution material until the same changeover point, as used for the determining of the error is reached. Repeat the above procedure until Max. of the instrument is reached.

Unload in reverse order to zero, i.e. unload the weights and determine the change over point. Place the weights back and remove the substitution material until the same changeover point is reached. Repeat this procedure until no-load is reached.

(5) Tare

(i) Tare weighing

Weighing tests shall be performed at least at two different tare values. At least 5 steps may be selected including Min. loads close to values at which mpe changes and the value close to the maximum possible load (or maximum additive tare if provided)

(6) Eccentricity test

Large weights should be used in preference to several small weights. The load shall be applied centrally in the segment if several weights are used.

The location of the load shall be marked on a sketch in the report.

The automatic zero-setting device shall not remain in operation during the sets.

(i) Instrument with load receptor having not more than four points of supports

The four quarter segments roughly equal to 1/4 of the surface of the load receptor shall be loaded in turn.

(ii) Instruments with a load receptor having more than four points of support

The load shall be applied over each support on an area of the same order of the magnitude as the fraction of 1/n of the surface area of the load receptor, where n is the number of points of support.

(iii) Instrument with special load receptor (tank, hopper)

The load shall be applied to each point of support.

(iv) Instrument used for weighing rolling loads

A rolling load shall be applied at different positions on the load receptor. These positions shall be at the beginning, the middle and at the end of the load receptor in the normal driving direction. The positions shall then be tested in the reverse direction.

(7) Discrimination test

The following tests shall be performed with three different loads, i.e. Min, 1/2 load and Max.

(i) Non-self indication and analogue indication

An extra load shall be placed gently on or removed from the load receptor while the instrument is at equilibrium.

(ii) Digital indication :

A load plus sufficient additional weights (say 10 times 1/10 of e) shall be placed on the load receptor. The additional weights shall then be removed until the indication, I is decreased unambiguously by one actual scale interval i.e. I-d. One of the additional weights shall be replaced and a load equal to 1.4 e shall then be placed gently on the load receptor and give a result, increased by one actual scale interval above the initial indication, i.e. I+d.

(8) Repeatability test

Two series of weighing shall be performed; one at 1/2 load and the other at max. Readings shall be taken when the instrument is loaded and unloaded.

(9) Creep test

Load the instrument close to Max. Take one reading as soon as the indication has stabilized and then note the indication while the load remains on the instrument for a period of four hours. During this test the temperature should not vary more than 2oC.

The test may be terminated after 30 minutes if the indication differs less than 0.5e during the first 30 minutes and the difference between 15 and 30 minutes is less than 0.2e.

9(10) Zero return test

The deviation in the zero indication before and after a period of loading with a load close to Max for half an hour, shall be determined. The reading shall be taken as soon as the indication has stabilized.

For multiple range instruments, continue to read the zero indication during the following 5 minutes after the indication has stabilized.

If the instrument is provided with automatic zero-setting or zero-tracking, it shall not be in operation.

Test for the stability of equilibrium (instruments with printing and/or data storage devices)

Load the instrument up to 50 per cent of Max. Manually disturb the equilibrium and initiate the command for data printing or data storage as soon as possible. Read the indicated value 5 seconds after printing. Perform the test 5 times.

(11) Influence factors

(i) Tilting

The instrument shall be tilted both forwards and backwards longitudinally, and from side to side transversely.

In the text that follows, class II instrument intended for direct sales to the public are designated class II* and class II instrument not intended for direct sale to the public are designated class II.

In practice the tests (no load and loaded) can be combined as follows:

After zero setting in the reference position, the indication is determined at no load and at the two test loads. The instrument is then unloaded and tilted (without a new zero setting), after which the indication at no load and at the two test loads are determined. This procedure is repeated for each of the tilting directions.

In order to determine the influence of tilting on the loaded instrument, the indication obtained at each tilt shall be corrected for the deviation from zero which the instrument had prior to loading.

If the instrument is provided with automatic zero-setting or zero tracking, it shall not be in operation.

Tilting class II, III and IIII instruments

(a) Tilting at no-load (class II*, III and IIII) :

The instrument shall be set to zero in its reference position (not tilted). The instrument shall then be tilted longitudinally up to 2/1000 or the limiting value of the level indicator, whichever is greater. The zero indication is noted. The test shall be repeated with transverse tilting.

(b) Tilting when loaded (class II, II*, III and IIII) :

The instrument shall be set to zero in its reference position and two weighings shall be carried out at a load close to the lowest load where the maximum permissible error changes, and at a load close to Max. The instrument is then unloaded and tilted longitudinally and set to zero. The tilting shall be 2/1000 or the limiting value of the level indicator, whichever is greater. Weighing tests as described above shall be performed. The test shall be repeated with transverse tilting.

(c) Tilting class I instrument :

The instrument shall be tilted longitudinally up to the limiting value of the level indicator. Check the tilt. Repeat with transverse tilting.

If the tilt is not greater than 2/1000, no further testing is required. Otherwise test as per “tilting when loaded (class II, II* III and IIII)” in (b) above.

(d) Instrument without level indicator :

For an instrument liable to be tilted and not fitted with a level indicator the test “tilting class II, III and IIII” as given in (a) and (b) shall be performed except that the instrument shall be tilted 5% instead of 0.2%.

(12) Warm up time test

An instrument using electric power shall be disconnected from the supply for a period of at least 8 hours prior to the test. The instrument shall then be connected and switched on and as soon as the indication has stabilized, the instrument shall be set to zero and the error at zero shall be determined. Calculation of error shall be made. The instrument shall be loaded with a load close to Max. These observations shall be repeated after 5, 15 and 30 minutes.

For instruments of class I, the provisions of the operating manual for the time following connection to the mains shall be observed.

(13) Temperature tests

See Figure 55E for practical approach to performing the temperature tests.

(i) Static temperature tests:

The test consists of exposure of the equipments under test (EUT) to constant temperatures within the range stated under free air conditions, for a 2 hour period after the EUT has reached temperature stability.

The weighing tests (loading and unloading) shall be carried out

- at a reference temperature (normally 20oC but for class I instruments the mean value of the specified temperature limits);

- at the specified high temperature;

- at the specified low temperature or at a temperature of 5oC if the specified low temperature is below 10oC; and

- at the reference temperature.

The change of temperature shall not exceed 1oC/min during heating and cooling down.

For class I instruments changes in barometric pressure shall be taken into account.

The absolute humidity of the test atmosphere shall not exceed 20 g/m 3 , unless the operating manual gives different specifications.

(ii) Temperature effect on the no-load indication :

The instrument shall be set to zero and then changed to the prescribed highest and lowest temperature as well as at 5oC if applicable. After stabilisation the error of the zero indication shall be determined. The change in zero indication per 1oC (class I) instrument or per 5oC (other instruments) shall be calculated. The changes of these errors per 1oC (class I instruments) or per 5oC (other instruments) shall be calculated for any two consecutive temperature of this test.

This test may be performed together with the temperature test. The errors at zero shall then be additionally determined immediately before changing to the next temperature and after the 2 hour period after the instrument has reached stability at this temperature.

Note: Pre-loading is not allowed before these measurements.

If the instrument is provided with automatic zero-setting or zero-tracking, it shall not be in operation.

(14) Voltage variation

Stabilize the EUT under constant environmental conditions.

The test consists of subjecting the EUT to variations of AC mains voltage.

The test shall be performed with test loads of 10e and a load between 1/2 Max and Max.

Test severity : Voltage variations :

Upper limit V + 10%

 

Lower limit V - 15%

Where V is the value marked on the instrument.

Maximum allowable variations : All functions shall operate as designed, and all indications shall be within the maximum permissible errors. If the instrument is provided with an automatic zero-setting or a zero tracking device, it may be in operation during the test.

(15) Endurance test :

(Applicable only to instruments of class II, III and IIII with Max < 100 kg

The endurance test shall be performed after all other tests.

Under normal conditions of use, the instrument shall be subjected to the repetitive loading and unloading of a load approximately equal to 50% of Max. The load shall be applied 100 000 times. The frequency and speed of application shall be such that the instrument attains an equilibrium when loaded and when unloaded. The force of the load applied shall not exceed the force attained in a normal loading operation.

A weighing test in accordance with the procedure shall be performed before the endurance test is started to obtain the intrinsic error. A weighing test shall be performed after the completion of the loadings to determine the durability error due to wear and tear. If the instrument is provided with automatic zero-setting or zero-tracking device it may be in operation during the test.

Annex-A

ADDITIONAL TESTS FOR ELECTRONIC INSTRUMENTS FOR MODEL APPROVAL

1. General requirements for electronic instruments under test (EUT)

Energise the EUT for a time period equal to or greater than the warm up time specified by the manufacturer and maintain the EUT energised for the duration of the test.

Adjust the EUT as closely as practicable to zero prior to each test, and do not re-adjust it at any time during the test, except to reset it if a significant fault has been indicated. The deviation of the no-load indication due to any test condition shall be recorded, and any load indication shall be corrected accordingly to obtain the weighing result.

The handling of the instrument shall be such that no condensation of water occurs on the instrument.

2. Performance tests for influence factors

2(1) Static temperatures.

2(2) Damp heat, steady state

(not applicable to class I instrument or class II instruments where e is less than 1 gram).

Test procedure in brief : The test consists of exposure of the EUT to a constant temperature and a constant relative humidity. The EUT shall be tested with at least five different test loads.

- at the reference temperature (20oC or the mean value of the temperature range whenever 20oC is outside this range) and a relative humidity of 50% following conditioning.

- at the high temperature of the range specified in clause (ii) of sub-paragraph (9) of paragraph 3 of Part II and a relative humidity of 85%, two days following temperature and humidity stabilization, and

- at the reference temperature and relative humidity of 50%.

Maximum allowable variations : All functions shall operate as designed.

All indications shall be within maximum permissible errors.

3. Power voltage variations

Performance tests for disturbances

(1) Short time power reductions

Test procure in brief : Stabilize the EUT under constant environmental conditions.

A test generator capable of reducing the amplitude of one or more half cycles (at zero crossings) or the AC mains voltage shall be used. The test geuerator shall be adjusted before connecting the EUT. The mains voltage reduction shall be repeated ten times with an interval of at least 10 seconds.

The test shall be performed with test loads of 10 e and a load between 1/2 Max and Max

Test severity
Reductions
100%
50%
Number of half cycles
1
2

Maximum allowable variations : The difference between the weight indication due to the disturbance and the indication without the disturbance shall either not exceed e or the instrument shall detect and react to a significant fault.

(2) Burst

The test consists in exposing the EUT to specified bursts of voltage spikes.

Before any test stabilize the EUT under constant environmental conditions.

The test shall be applied separately to:

power supply lines,

I/O circuits and communications lines, if any.

The test shall be performed with test loads of 10 e and a load between 1/2 Max and Max.

Test severity : Open circuit output test voltage for:

- power supply lines 1 kV

- I/O signal 1, data and control lines 0.5kV.

Maximum allowable variations : The difference between the weight indication due to the disturbance and the indication without the disturbance shall either not exceed e or the instrument shall detect and react to a significant fault.

(3) Electrostatic discharge

The test, consists in exposing the EUT to specified, direct and indirect, electrostatic discharges.

This test includes the paint penetration method, if appropriate, for direct discharges the air discharge shall be used where the contact discharge method cannot be applied.

Before any test stabilize the EUT under constant environmental conditions.

At least 10 direct discharges and 10 indirect discharges shall be applied. The time interval between successive discharges shall be at least 10 seconds.

The test shall be performed with test loads of 10e and a load between 1/2 Max. and Max.

Maximum allowable variations : The difference between the weight indication due to the disturbance and the indication without the disturbance shall either not exceed e or the instrument shall detect and react to a significant fault.

(4) Immunity to radiated electromagnetic fields

The test consists in exposing the EUT to specified electromagnetic fields.

Before any test, stabilize the EUT under constant environmental conditions.

The EUT shall be exposed to electromagnetic fields of the strength and character as specified by the severity level.

The test shall be performed with one small test load only :

Frequency range
26-1000
MHz
Field strength
3
V/m
Modulation
80% AM
1 kHz sine wave

Maximum allowable variations : The difference between the weight indication due to the disturbance and the indication without the disturbance either shall not exceed e or the instrument shall detect and react to a significant fault.

4. Span stability test

(Not applicable to class I instruments)

Test procedure in brief : The test consists in observing the variations of the error of the EUT under sufficiently constant ambient conditions (reasonably constant conditions in a normal laboratory environment) at various intervals before, during and after the EUT has been subjected to performance tests.

The performance test shall include the temperature test and if applicable, the damp heat test; they shall not include any endurance test; other performance test in this Annexure and in paragraph 9 shall be performed.

The EUT shall be disconnected from the mains power supply, or battery supply where fitted, two times for at least 8 hours during the period of the test. The number of disconnections may be increased if the manufacturer specified so or at the discretion of the approval authority in the absence of any such specification.

For the conduct of this test the manufacturer's operating instructions shall be considered.

The EUT shall be stabilised at sufficiently constant, ambient conditions after switch-on for at least 5 hours, but at least 16 hours after the temperature and damp heat test have been performed.

Test duration : 28 days or the period necessary for the performance tests to be carried out, whichever is shorter.

Time between measurements : Between 1/2 and 10 days.

Test load : Near Max : The same test weights shall be used throughout this test.

Number of measurement at least 8.

Test sequence : Stabilize all factors at sufficiently constant ambient conditions.

Adjust the EUT as close to zero as possible.

Automatic zero-tracking shall be made inoperative and automatic built in span adjustment device shall be made operative.

Apply the test weight(s) and determined the error.

At the first measurement immediately repeat zeroing and loading four times to determine the average value of the error. For the next measurements perform only one unless either the result is outside the specified tolerance or the range of the five readings of the initial measurements is more than 0. 1e.

Record the following data:—

(a) data and time

(b) temperature

(c) barometric pressure

(d) relative humidity

(e) test load

(f) indication

(g) errors

(h) changes in test locations

and apply all necessary corrections resulting from variations of temperature, pressure, etc. between the various measurements.

Allow full recovery of the EUT before any other test are performed.

Maximum allowable variations

The variation in the errors of indication shall not exceed half the verification scale interval or half the absolute value of the maximum permissible error on initial verification or the test load applied, whichever is greater, on any of the n measurements.

Where the difference of the results indicate a trend more than half the allowable variation specified above, the test shall be continued until the trend comes to rest or reverses itself, or until the error exceeds the maximum allowable variation.

“HEADING B”
[ PART I]
GENERAL REQUIREMENTS

1. Category

Weighing instruments of the following categories are included in this Part:

(a) Beam Scales

(b) Counter Machines

2. Constructions

(a) Weighing instruments shall be of such materials, design and construction that under normal conditions of service:

(i) They maintain accuracy.

(ii) They function satisfactorily without the need for frequent adjustment.

(iii) Excessive stresses do not develop in the vital parts.

(b) The pivots, knife-edges and bearings, wherever used shall be of agate or suitable hard material or of suitable quality steel. The steel knife-edges and bearings shall have the hardness specified below:

(i) For beam scale of classes C and D and with capacities 10kg. and below not less than 54 Rockwell C.

(ii) For other weighing instruments-60 to 66 Rockwell C.

(c) The pivots, knife-edges and bearings shall be protected against corrosion and dirt.

3. Marking

(a) All weighing instruments shall carry the following markings:—

(i) manufacturer's name, or his registered trade mark.

(ii) to weight ........ t, kg, or g as appropriate.

(iii) class, wherever applicable.

Note: The manufacturer's name or registered trade marks shall be such as will not be mistaken for the stamp or seal of the verification authority.

(b) The markings shall be indelible and of a size, shape and clarity allowing easy reading under normal conditions of use of the instruments.

(c) All numerals appearing on weighing instruments shall be international form of Indian numeral.

4. Sealing

All weighing instruments shall be provided by the manufacturers with a plug or stud of soft metal to receive the stamp or seal of the verification authority. Such plug or stud shall be provided in a conspicuous part of the instrument and shall be made in such a manner as to prevent its removal without obliterating the seal.

PART II
BEAM SCALES

1. Definitions

(a) Beam Scale—A weighing instrument with equal arms having three knife edges, three bearings, an indicator (pointer) in the centre, and pans suspended from the end knife-edges.

(b) Sensitivity figure—It is expressed in terms of miligrams per division.

(c) Sensitiveness—It is expressed as the least weight, required to be added to or removed from one of the pans, to cause a visible displacement of the pointer from its position of equilibrium.

Note: 1. Sensitivity figures shall be determined only for those beam scales which have a pointer with sector plate. For other beam scales the sensitiveness test shall apply.

2. All class ‘A' beam scales shall be provided with a pointer with sector plate or the scale.

(d) Error (Due to inequality of arms)—The error due to inequality of arms of a beam scale under specified load conditions is equal to the mass of the additional weights required to bring to equipoise the balance, carrying weights of equal masses in the pans.

(e) Greatest Error (Due to Inequality of Arms)—The greatest error due to inequality of arms is the error determined with two weights each equal to the capacity (full load) of the balance.

2. Classes and Capacities

(a) Beam scales shall be of any one of the four classes namely, A, B, C or D, based on limits for sensitivity figure/sensitiveness and greatest error specified in Tables 43-B to 43-E, respectively.

(b) Beam scales of the different classes shall be of one of the capacities mentioned in Tables 43-B to 43-E.

(c) The trades for which the different classes of scales may be used are:

Class of Scale
Use
A
* Commercial assay and in ‘Dharam Kanta' for verifying the weights of
bullion and precious stones.
B

Precious stones, jewels, pearls, bullion, precious metals, saffron and
similar expensive commodities, chemists and druggists preparations,
perfumery, etc.

C

Base metals and commodities such as cereals, tea, coffee, tobacco, jute,
cotton, dry fruits, spices, oil seeds, etc.

D

Weighment of cheaper commodities such as scrap iron, fuel, wood,
charcoal, vegetables, etc.

* Single pan balances may also be used in place of Class A or B beam scales. (For tests to be conducted on such balances see annexure at the end of this part.)

TABLE 43B
LIMITS FOR SENSITIVITY FIGURE AND GREATEST ERROR FOR BEAM SCALES
Class ‘A'

Capacity
Verification

Inspection

Sensitivity figure per division of scale at no load and at full load
Greatest error allowed when fully loaded
Sensitivity figure per division of scale at no load and at full load
Greatest error allowed when fully loaded
1
2
3
4
5
mg
mg
mg
mg
2 g
0.02
0.04
0.06
0.08
5 g
0.05
0.10
0.15
0.20
10 g
0.10
0.20
0.30
0.40
20 g
0.20
0.40
0.60
0.80
50 g
0.50
1
1.5
2
100 g
1
2
3
4
200 g
2
4
6
8
500 g
5
10
15
20
1 kg
10
20
30
40
2 kg
20
40
60
80
5 kg
30
60
90
120
10 kg
50
100
150
200
20 kg
100
200
300
400
50 kg
200
400
600
800

TABLE 43C
LIMITS FOR SENSITIVENESS AND GREATEST ERRORS FOR BEAM SCALES
Class ‘B'

Capacity
Verification

Inspection

Sensitiveness at full load
Greatest error allowed when fully loaded
Sensitiveness at full load
Greatest error allowed when fully loaded
1
2
3
4
5
2 g
1 mg
2 mg
3 mg
4 mg
5 g
2 mg
4 mg
6 mg
8 mg
10 g
3 mg
6 mg
9 mg
12 mg
20 g
5 mg
10 mg
15 mg
20 mg
50 g
10 mg
20 mg
30 mg
40 mg
100 g
20 mg
40 mg
60 mg
80 mg
200 g
30 mg
60 mg
90 mg
120 mg
500 g
50 mg
100 mg
150 mg
200 mg
1 kg
100 mg
200 mg
300 mg
400 mg
2 kg
200 mg
400 mg
600 mg
800 mg
5 kg
300 mg
600 mg
900 mg
1.2 g
10 kg
500 mg
1 g
1.5 g
2 g
20 kg
1 g
2 g
3 g
4 g
50 kg
2 g
4 g
6 g
8 g
100 kg
5 g
10 g
15 g
20 g
200 kg
10 g
20 g
30 g
40 g

TABLE 43D
LIMITS OF SENSITIVENESS AND GREATEST ERRORS FOR BEAM SCALES
Class ‘C'

Capacity
Verification
Inspection
Sensitiveness at full load
Greatest error allowed when fully loaded
Sensitiveness at full load
Greatest error allowed when fully loaded
1
2
3
4
5
100 g
100 mg
200 mg
300 mg
400 mg
200 g
200 mg
400 mg
600 mg
800 mg
500 g
500 mg
1 g
1.5 g
2 g
1 kg
1 g
2 g
3 g
4 g
2 kg
2 g
4 g
6 g
8 g
5 kg
3 g
6 g
9 g
12 g
10 kg
5 g
10 g
15 g
20 g
20 kg
10 g
20 g
30 g
40 g
50 kg
15 g
30 g
45 g
60 g
100 kg
25 g
50 g
75 g
100 g
200 kg
50 g
100 g
150 g
200 g
300 kg
75 g
150 g
225 g
300 g
500 kg
100 g
200 g
300 g
400 g
1000 kg
150 g
300 g
450 g
600 g

TABLE 43E
LIMITS OF SENSITIVENESS AND GREATEST ERRORS FOR BEAM SCALES
Class ‘D'

Capacity
Verification

Inspection

Sensitiveness at full load
Greatest error allowed when fully loaded
Sensitiveness at full load
Greatest error allowed when fully loaded
kg
g
g
g
g
1
2
3
4
5
5
5
10
15
20
10
10
20
30
40
20
20
40
60
80
50
30
60
90
120
100
50
100
150
200
200
100
200
300
400
300
150
300
450
600
500
200
400
600
800
1000
300
600
900
1200

3. Materials

(a) Material for Class A Beam Scales—Class A beam scales shall be made of non-magnetic materials only, except knife-edges and bearings.

(b) Material for other Class of Beam Scales—Beams and pans shall be made of stainless steel, mild steel, brass or bronze. Aluminium alloy may be used in balances, having a capacity of not more than 50g. The pans of Class B beam scales may be made of glass also. In the case of beam scales of Classes C and D, pans of hard-wood shall be permitted for capacities 100 kg. and above. The pans of beam scales, when made of timber, shall be adequately re-inforced and protected against wear.

(c) Suspension—Pans shall be suspended from the heam by metal chains through stirrups, hooks or rings. In the case of Class B beam scales of capacity 100 g or less, the pans may be suspended by silk or nylon threads.

(d) All mild steel parts used in beam scales shall be suitably protected against rust.

4. Construction

(a) Knife-edges and Bearings

(i) The knife-edges and bearings used in beam scales shall be of one of the following types:—

Agate-box —Wherein agates bearings are fitted in a brass or iron box, with side holes which permit the projecting ends of the knife-edges to pass into the boxes and rest on or rise to their bearings (See Fig 55-F).

AGATE BOX BEAM

Figure-55F

Dutch-end —Wherein the end bearings are fixed inside plates bolted together across the beam to form a shackle (See Fig. 55-G)

DUTCH-END BEAM
Figure-55G

Swan-neck —Wherein the ends are curved and slotted, the bottom of the slot forming a knife-edge, the extremeties of the beam being widened in direction at right angles to its length so that the base of the slot is parallel to the central knife-edge (See Fig. 55-H).

SWAN NECK BEAM
Figure-55H

‘Continuous knife-edge' —Wherein the knife-edges bear along their whole length (See Fig 55-I)








CONTINUOUS KNIFE
Figure55-I

(ii) Class A beam scales shall have continuous knife-edges and shall be provided with means for relieving all the knife-edges from the bearings.

(iii) Class B, beam scale shall not have swan-neck fittings.

(b) Glass Case

Every beam scale of Class A shall be provided with a glass case. It shall also be provided with bubble or a plumb line and levelling screws to facilitate levelling of the instrument.

(c) Leading Dimensions

(i) No dimensions have been specified for Class A beam scales.

(ii) Beam scale of Classes B, C and D shall have the leading dimensions specified in Tables 43-F to 43-J and Fig. 55-J to 55-N as applicable to within the tolerances specified in 4(d). For Class C beam scales of capacities 5 kg and below fixed hooks may also be provided

TABLE 43F
LEADING DIMENSIONS OF BEAM
Class B (with pointer above the beam)

Capacity
Length between ends (Nominal)
Depth at the centre (Nominal)
Thickness of plate at the centre (Nominal)
L
D
T
1
2
3
4
mm
mm
mm
FLAT TYPE
2 g
70
10
2
5 g
95
12
2
10 g
110
15
2
20 g
120
20
3
50 g
135
22
3
100 g
150
25
4
200 g
170
25
5
500 g
200
30
5
1 kg
250
40
6
2 kg
300
45
6
5 kg
450
50
6
10 kg
500
58
8
20 kg
600
58
10
50 kg
750
100
15
100 kg
1000
110
18
200 kg
1250
125
25
OPEN PATTERN (BRIDGE) TYPE
200 g
170
25
5
500 g
260
37
5
1 kg
310
44
5
2 kg
350
48
5
5 kg
450
60
6
10 kg
500
70
8
20 kg
600
80
10
50 kg
750
120
15
100 kg
1000
150
20

TABLE 43G
Leading dimensions of Beam
Class B (Flat and Open Pattern Type with
pointer below the beam)

Capacity
Length between the ends (Nominal)
Depth at the centre (Nominal)
Thickness of plate at the centre knife edge (Nominal)
A
L
D
T
1
2
3
4
mm
mm
mm
2 g
70
3
2
5 g
95
3
2
10 g
110
4
2
20 g
120
20
3
50 g
135
20
3
100 g
150 g
20
4
200 g
200
20
6
500 g
235
25
8
1 kg
300
30
8
2 kg
320
30
8
5 kg
350
32
10
10 kg
400
40
12
20 kg
500
50
14
50 kg
700
70
18
100 kg
800
80
20
200 kg
1250
125
25

TABLE 43H
LEADING DIMENSIONS OF BEAM
Class C (Swan Neck Type)

Capacity
Length between the ends (Nominal)
Depth at the centre (Nominal)
Thickness of plate at the centre knife edge (Nominal)
L
D
T
1
2
3
4
mm
mm
mm
100 g
150
30
4
200 g
200
40
5
500 g
300
40
6
1 kg
350
45
6
2 kg
400
4
6
5 kg
550
70
6
10 kg
600
80
6
20 kg
750
108
8
50 kg
900
116
8
100 kg
1200
138
14
200 kg
1350
148
16
300 kg
1650
154
18
500 kg
1800
178
25
1000 kg
2000
200
32

FIG. 55M

TABLE 43I
LEADING DIMENSIONS OF BEAM
Class C (Dutch End Type)

Capacity
Length between end knife-edges (Nominal)
Depth at the centre (Nominal)
Thickness of plate at the centre knife-edge (Nominal)
L
D
T
1
2
3
4
mm
mm
mm
100 g
150
35
4
200 g
200
40
5
500 g
300
40
6
1 kg
350
45
6
2 kg
400
45
6
5 kg
450
70
6
10 kg
450
75
8
20 kg
600
75
8
50 kg
750
80
8
100 kg
900
120
14
200 kg
900
133
16
300 kg
1050
142
16
500 kg
1350
192
20
1000 kg
1650
203
25

FIG. 55N
TABLE 43J
LEADING DIMENSIONS OF BEAM
Class ‘D'

Capacity
Length between the end knife-edges (Nominal)
Depth at the centre (Nominal)
Thickness of plate at the centre (Nominal)
L
D
T
1
2
3
4
kg
mm
mm
mm
SWAN-NECK WITH FIXED FLAT HOOKS
5
550
70
6
10
600
80
6
20
750
108
6
50
900
116
8
100
1200
138
14
200
1350
148
16
300
1650
154
18
DETACHABLE FLAT HOOKS
500
1800
178
25
1000
2000
200
32

Note: Class D beam scales shall be distinguished from Class C scale by the existence of two identical holes 5 to 10 mm in diameter through the beam, one on either side of the central knife-edge.

(d) Permissible variation in Dimensions —The dimensions of the beam scales shall not vary by more than 10 percent of the dimensions prescribed in Tables 43-F to 43-J.

(e) Attachment for Adjusting the Balance of a Beam scale —Beam scales of Classes B, C and D may be provided with a balance ball or balance box securely attached to one of the suspended chains or pans in such a manner that it is not possible to alter it easily. The balance ball or balance box shall not be so large as to contain more loose material than an amount exceeding one percent in weight of the capacity of beam scales under 100 kg or an amount exceeding 1 kg for beam scale of capacity 100 kg and above.

(f) Arrangement adjusting sensitivity figure —Beam scales of Class A shall be provided with an attachment for adjusting the sensitivity figure. Beam scales of other classes shall not be provided with an attachment to adjust their sensitiveness.

(g) For the purposes of postal transactions Class C beam scales may be provided with an open type pan as illustrated in Fig. 55-O.

FIG. 55-O

5. Tests

(a) Test for sensitivity figure or sensitiveness Only --Class ‘A' beam scales shall be tested for sensitivity figure. The sensitivity figure shall be determined at zero and full loads and shall comply with the requirements specified in Table 43-B, Beam scales other than Class ‘A' shall be tested for sensitiveness at full load only and shall comply with the requirements specified in Tables 43-C to 43-E.

(i) Class A Beam Scales —For determining the sensitivity figure of a Class A beam scale at no load, the beam scale shall be properly balanced without any load in the pans. A small weight whose mass is accurately known shall be put on one of the pans. This small weight shall be so chosen that the turning points of the pointer remain within the reading index. The rest point shall be determined by the usual oscillation method. The weight shall then be transferred to the other pan and the second rest point shall be determined. If the rest points shift by ‘n' divisions on the scale and if the mass of the test weight is ‘w' mg., the sensitivity figure ‘s' in miligrams per division, at no load, is given by the relation:

s = 2w/n

A similar test with appropriate weights in each pan representing the full capacity of the beam scale, shall be performed to determine the sensitivity figure of the beam scale at full load.

(ii) Class A beam scales 2g to 20g —As it is not practicable to make weights of denominations smaller than one milligram, the sensitivity figure of beam scales of smaller capacities, that is, from 2 g to 20 g shall be determined by means of a pair of weights, each weight having a mass of approximately 5 mg. The difference in the masses of the two weights of the pair shall be adjusted to be of the order of 0.05 mg, 0.12 mg., 0.25 mg, or 0.5 mg depending on the beam scale under test, that is, for testing 2 g, 5 g, 10 g or 20 g, beam scale, respectively. This difference should be known accurately. After balancing the beam scale at zero load, one of the two weights in the pair shall be put on the right pan and the other weight on the left pan. The rest point shall be determined. The two weights shall then be inter-changed and the second rest point shall be similarly determined. If the rest point shifts by ‘n' divisions and if the difference between the masses of the two test weight is ‘w' mg., the sensitivity figure ‘s' of the beam scale in milligrams per division at zero load is given by the relation:

s = 2w/n

To determine the sensitivity figure of the beam scale at full load a similar test shall be performed with weights equal to the maximum capacity of the beam scale in each pan.

(iii) Beam scales other than class A —Pans of a beam scale other than Class A, shall be loaded with weights representing its full capacity and the scale is balanced. Weights of such mass shall then be added on one of the pans as may move the tip of the pointer from its equilibrium position by an appreciable distance. After removing these weights the same test shall be repeated on the other pan and the weights required for moving the tip of the pointer by the same distance on the other side of the equilibrium position shall then be added. If these weights are denoted by ‘w1 ' and ‘w2 ' respectively, the sensitiveness “s” of the beam scale is given by the relation:

s = W1 +W2
__________

2

(b) Inequality of Arms Test

(i) Class A Beam Scale —The error due to inequality of arm of Class A beam scale shall be determined by the following method. The beam scale shall be properly balanced without any load in the pans. The rest point (R0) shall be determined by the usual oscillation method. After arresting the beam both the pans shall be loaded with equal weights of same material and representing the full capacity of the beam scale. The beam scale shall then be properly balanced by adding small weights. The rest point (R1) shall be determined by the oscillation method. After arresting the beam, the loads, including the small weights, shall be interchanged and scale balanced again by putting additional weights (m), if necessary on one of the pans. The rest point (R2) shall again be determined. The error (E) caused due to inequality of the arms of the scale is given by

E = m + [ R1+R2-2R0]S
2
2

where S is the sensitivity figure of the beam scale.

(ii) Beam scales other than Class A —In the case of beam with fixed hooks the beam with hooks but without chains and pans shall be checked for balance. If detachable hooks are provided the beam alone shall be checked. The loose hooks shall then be attached and the assembly checked for balance. The chains and pans shall then be attached in the case of both the types of balances and checked again for balance.

After checking at no load, each of the pans shall be loaded with weights equal to the maximum capacity of the beam scale and the scale shall be balanced.

The loads thereon shall then the interchanged and the beam scale balanced again by adding necessary weights on one of the pans. The additional weight shall be equal to twice the error due to inequality of arms of the beam.

In the case of beams with attached hooks, the loads shall be interchanged along with the chains, and pans and in the case of beams with detachable hooks the loads shall be interchanged along with the hook chains and pans.

(iii) The figure so obtained shall be halved to determine the error at full-load. These should be within the limits specified in Tables 43-B to 43-E.

(c) Shift Test —Beam scales other than Class A—With the pans loaded to half the capacity, no appreciable difference in the accuracy of the instrument shall result from moving the knife-edges or bearings laterally or backwards and forwards within their limits of movement.

Similarly when the above load is moved to any position on the pan, the difference shown shall not be appreciable.

Note: The words ‘appreciable difference' shall mean ‘a difference which can be detected', but the Legal Metrology Officer should exercise his discretion in each particular case.

6. Sealing

All beam scales shall be provided by the manufacturer with a plug/plugs or stud/studs of soft metal to receive the stamp or seal of the verification authority. Such plug/plugs or stud/studs shall be provided in a conspicuous position and shall be made in such a manner as to prevent its removal without obliterating the seal/seals.

ANNEXURE

Tests for single pan balances

1. Sensitiveness —The balance shall be tested for sensitiveness near zero, middle and extreme position of the projection scale under three conditions of loading namely no load, half load and full load. The balance shall be such so as to record the change in mass of the order of 1 sub-division of the projection scale accurately within the limits of the value equivalent to the least count of the vernier or micrometre scale if provided, otherwise within half a division of the projection scale.

2. Accuracy of projection scal e—The accuracy of the projection scale shall be examined at 10 points of the scale under three different conditions of loading namely at no load, half load and full load. The maximum error at any point shall not exceed the value of the one half-sub-division of the projection scale, if no vernier or micrometer scale is provided or two divisions of the vernier or micrometre scale.

3. Consistency of performanc e—Ten consecutive readings shall be noted by releasing and arresting the balance in the unloaded condition followed by another ten readings when the balance is in fully loaded condition. The standard deviation from the mean of the rest point shall be calculated separately for each condition, which in no case shall exceed half the division of the projection scale if no vernier or micrometre scale is provided or two divisions of the vernier or micrometre scale.

PART III
COUNTER MACHINES

1. Definition

A counter machine is an equal arm weighing instrument of capacity not exceeding 50 kg, the pans of which are above the beam. Figure 55-P illustrates a typical counter machine.

2. Capacities

The machines may be of the following maximum capacities:—

500g, 1kg, 2kg, 3kg, 5kg, 10kg, 15kg, 20kg, 25kg, 30kg and 50kg.

3. General Requirements

(a) When the beam of body has two sides, they shall be connected further by not less than two cross-bars. The supports for the pans shall be of a suitable rigid structure such as cross members strengthened by straps. Central pieces or forks shall be fixed so that they are not twisted or dislocated.

(b) Bearing surfaces, knife-edges and points of contact of all stays, hooks and loops shall be of hard steel or agate. The knife-edges and bearings shall be so fitted as to allow the beam to move freely. The knee-edges shall rest upon the bearings along the whole length of their working part.

(c) A counter machine may have a balance box for minor adjustments. In such a case, the balance box shall be permanently fixed beneath the weight pan and shall be large enough to contain loose material to an amount upto one per cent of the capacity of the machine. No other adjusting contrivance shall be used.

(d) The pans may be made of any suitable material such as mild steel, stainless steel, brass or bronze, aluminum or its alloys, porcelain, enamel coated steel, glass or plastic material. They may be of any convenient shape.

(e) The minimum fall of the extremeties of the beam, either way, of counter machines shall be as follows:—

Capacity

Minimum fall

500 g, 1 kg and 2 kg
6 mm
3 kg, 5 kg, 10 kg, 15 kg
10 mm
20 kg, 25 kg and 30 kg
12 mm
50 kg
13 mm

4. Tests

(a) The machine shall be tested on a horizontal level plane.

(b) Sensitiveness and Error

(i) The machine shall be tested for sensitiveness at full load with the beam in a horizontal position. The addition of the weight specified in col. 2 or 4 as the case may be of Table 43-K shall cause the pointer to have a displacement corresponding to the minimum limits specified in paragraph 3(e).

(ii) The error that is the weight required to bring the beam of the instrument to horizontal position when fully loaded with weights each equal to its capacity on both pans shall not exceed the limits specified in cols. 3 and 5 as the case may be of Table 43K.

(c) Shift Test

(i) When the goods pan is in the form of a scoop, the counter machine shall be correct to the prescribed limits of error if half the full load is placed against the middle of the back of the scoop and the other half at any position on the scoop.

(ii) When the goods pan is not in the form of a scoop, the counter machine shall indicate the same weight within half the prescribed limits of error, if the centre of a load equal to half the capacity placed on the goods pan is moved any where within a distance from the centre equal to one-third of the length of the pan. If the pan has a vertical side against the middle of that side, the weight being entirely on the weight pan, but in any position on it.

TABLE 43K
SENSITIVENESS AND MAXIMUM PERMISSIBLE ERRORS FOR COUNTER MACHINES

Verification

Inspection

Capacity
Sensitiveness when fully loaded
Maximum permissible error, in excess or deficiency, when fully loaded
Sensitiveness when fully loaded
Maximum permissible error, in excess or deficiency, when fully loaded
1
2
3
4
5
500 g
1.5 g
2.2 g
4.5 g
4.5 g
1 kg
2.0 g
3.0 g
6.0 g
6.0 g
2 kg
3.0 g
4.5 g
9.0 g
9.0 g
3 kg
4.0 g
6.0 g
12.0 g
12.0 g
5 kg
6.0 g
9.0 g
18.0 g

18.0 g

10 kg
7.0 g
10.5 g
21.0 g
21.0g
15 kg
8.0 g
12.0 g
24.0 g
24.0 g
20 kg
9.0 g
13.5 g
27.0 g
27.0 g
25 kg
10.0 g
15.0 g
30.0 g
30.0 g
30 kg
11.0 g
20.0 g
33.0 g
40.0 g
50 kg
15.0 g
30.0 g
45.0 g
60.0 g

5. Sealing

Each machine shall be provided with a plug or stud of soft metal on a conspicuous part of the beam or body to receive the stamp or seal of the verification authority. Such a plug or stud shall be made irremovable by undercutting it or by some suitable method.

“HEADING—C”
PART I
AUTOMATIC RAIL-WEIGHBRIDGES TERMINOLOGY
(Terms and definitions)

1. General definitions

1(1) Weighing instrument

Measuring instrument that serves to determine the mass of a load by using the action of gravity.

1(2) Automatic weighing instrument

An instrument that weighs without the intervention of an operator and follows a predetermined program of automatic processes characteristic of the instrument.

1(3) Rail-weighbridge :

A weighing instrument having a load receptor, inclusive of rails for conveying railway vehicles.

1(4) Electronic instrument

An instrument equipped with electronic devices.

1(5) Control instrument

A non-automatic weighing instrument used to determine the mass of a reference wagon.

1(6) Weigh zone

Zone in which a wagon must be located when it is weighed.

2. Construction

Note: In this Recommendation the term “device” is applied to any part which uses any means to perform one or more specific functions.

2(1) Load receptor

The part of the weigh zone that is intended to receive the load and which realizes a change in the balance of the instrument when a load is placed upon it.

2(1)(i) Multiple load receptors

Two or more load receptors placed in series that are used as a single load receptor for full draught weighing.

2(1)(ii) Aprons

The parts of the weigh zone that are not the load receptor nor part of the load receptor.

2(2) Electronic device

A device comprised of electronic subassemblies and performing a specific function. An electronic device is usually manufactured as a separate unit and is capable of being independently tested.

2(2)(i) Electronic sub-assembly

A part of an electronic device comprised of electronic components and having a recognizable function of its own.

2(2)(ii) Electronic component

The smallest physical entity that uses electron or hole conduction in semiconductors, gases, or in a vacuum.

2(3) Indicating device

The part of the instrument that displays the value of a weighing result in units of mass.

2(4) Ancillary devices

2(4)(i) Zero-setting derice

The means used to set to zero the weight indicating device when the load receptor is empty:

(a) Non-automatic zero-setting device : A zero-setting device that must be operated manually.

(b) Semi-automatic zero-setting device : A zero-setting device that operates automatically following a manual command.

(c) Automatic zero-setting device : A zero-setting device that operates automatically and without the intervention of an operator.

2(4)(ii) Printing device

The means to print the weight values of wagons weighed on the instrument and/or a summation of those wagon weights.

3. Metrological characteristics

3(1) Weighing

3(1)(i) Full draught weighing

Weighing a wagon that is entirely supported on the load receptor(s).

3(1)(ii) Partial weighing

Weighing a wagon in two or more parts on the same load receptor. The results are automatically added to indicate or print the wagon weight.

3(1)(iii) Weighing-in-motion (wim)

Weighing objects that are in motion.

3(1)(iii)(a) Uncoupled wagon weighing :

Weighing-in-motion of wagons that travel independently across a load receptor. (This is usually achieved by means of an incline of the approach to the load receptor)

3(1)(iii)(b) Coupled wagon weighing :

Weighing-in-motion of a train of coupled wagons to obtain a weight indication or printout of the individual wagons.

3(1)(iii)(c) Train weighing :

Weighing-in-motion of a number of coupled wagons to obtain a totalized weight of all the wagon weights.

3(1)(iv) Static weighing

Weighing a wagon while stationary and uncoupled to obtain a weight for the purposes of testing.

3(2) Capacity

3(2)(i) Maximum capacity (Max)

The largest load that an instrument is designed to weigh-in-motion without totalizing.

3(2)(ii) Minimum capacity (Min)

The load below which a weighing-in-motion result before totalizing may be subject to an excessive relative error.

3(3) Wagon weight

3(3)(i) Maximum wagon weight

The largest in-motion load that the installation is approved to weigh for a particular site.

3(3)(ii) Minimum wagon weight

The wagon weight below which a weighing-in-motion result may be subejct to an excessive relative error.

3(4) Scale interval (d)

A value expressed in units of mass for weighing-in-motion that is the difference between:

the values corresponding to two consecutive scale marks for analogue indication, or

two consecutive indicated or printed values for digital indication.

(i) Scale interval for stationary load : The scale interval used for static tests.

3(5) Speed

3(5)(i) Maximum operating speed : The greatest velocity of a wagon that the instrument is designed to weigh-in-motion and above which the weighing results may be subject to an excessive relative error.

3(5)(ii) Minimum operating speed : The lowest velocity of a wagon that the instrument is designed to weigh-in-motion and below which the weighing results may be subject to an excessive relative error.

3(5)(iii) Range of operating speeds : The difference between the minimum and maximum operating speeds at which a wagon may be weighed-in-motion.

3(5)(iv) Maximum transit speed : The maximum speed that a railway vehicle can travel on the weighzone without producing a permanent shift in the performance characteristics of a weighing instrument beyond those specified.

3(6) Warm-up time

The time between the moment that power is applied to an instrument and the mement at which the instrument is capcable of complying with the requirements.

3(7) Durability

Ability of an instrument to maintain its performance characteristics over a period of use.

4. Indications and errors

4(1) Methods of indication

4(1)(i) Analogue indication :

An indication allowing the determination of an equilibrium position to a fraction of the scale interval.

4(1)(ii) Digital indication :

An indication in which the scale marks are a sequence of aligned figures that do not permit interpolation to a fraction of a scale interval.

4(2) Errors

4(2)(i) Error (of indication) :

The indication of an instrument minus the (conventional) true value of the mass.

4(2)(ii) Intrinsic error :

The error of an instrument under reference conditions

4(2)(iii) Initial intrinsic error :

The intrinisc error of an instrument as determined prior to performance tests and durability evaluations.

4(2)(iv) Fault :

The difference between the error of indication and the intrinsic error of a weighing instrument.

Note 1: Principally, a fault is the result of an undesired change of data contained in or flowing through an electronic instrument.

Note 2: From the definition it follows that in this specification a “fault” is a numerical value.

4(2)(v) Significant fault :

A fault greater than d. The following are not considered to be significant faults:

- faults that result from simultaneous and mutually independent causes in the instrument or in its checking facility,

- faults that imply the impossibility of performing any measurement,

- transitory faults that are momentary variations in the indications which cannot be interpreted, memorized or transmitted as a measurement result,

- faults that are so serious that they will inevitably be noticed by those interested in the measurement.

4(2)(vi) Span stability :

The capability of an instrument to maintain the difference between the indication of weight at maximum capacity and the indication at zero within specified limits over a period of use,

4(2)(vii) Maximum span stability error :

A span stability error greater than one half of the absolute value of the maximum permissible error applicable to the load.

4(2)(viii) Rounding error :

The difference between a digitial measurement result (indicated or printed) and the value of the measurement result with an analogue indication.

5. Influence quantity

5(1) A quantity that is not the subject of the measurement but which influences the value of the measureu and or the indication of the instrument.

5(1)(i) Influence factor :

An influence quantity having a value within the specified rated operating conditions of the instrument.

5(1)(ii) Disturbance :

An influence quantity having a value that falls within the limits specified in this specification but that falls outside the rated operating conditions of the instrument.

5(2) Rated operating conditions :

Conditions of use which give the ranges of the influence quantities for which the metrological characteristics are intended to lie within the specified maximum permissible errors.

5(3) Reference conditions :

A set of specified values of influence factors fixed to ensure valid intercomparison of the results of measurements.

6. Tests

6(1) Static test :

A test with standard weights or a load that remains stationary on the load receptor to determine an error.

6(2) In-motion (dynamic) test :

A test with reference wagons that are in motion on the load receptor to determine an error.

6(3) Simulation test :

A test carried out on a complete instrument or part of an instrument in which any part of the weighing operation is simulated.

6(4) Performance test :

A test to verify that the equipment under test (EUT) is capable of accomplishing its intended functions.

6(5) Span stability test :

A test to verify that the EUT is capable of maintaining its performance characteristics over a period of use.

7. Rail vehicles

7(1) Wagon :

A loaded or unloaded railway goods vehicle that is recognized by the instrument as a vehicle to be weighed.

7(2) Reference wagon :

A wagon of known weight that is typical of those to be used for weighing on the instrument and which has been selected for the purposes of in-motion testing.

7(3) Total train :

A number of coupled wagons whose totalized weight is to be obtained.

PART II
METROLOGICAL AND TECHNICAL REQUIREMENTS

1. Scope

1(1) This part specifies the requirements and test methods for automatic rail-weigh-bridges, hereinafter referred to as “instruments” that are used to determine the mass of railway wagons, when they are weighed in motion.

2. Metrological Requirements

2(1) Accuracy classes :

Instruments are divided into four accuracy classes as follows:—

0.2, 0.5, 1, 2

An instrument may be in a different accuracy class for wagon weighing than that for train weighing.

2(2) Maximum permissible errors

2(2)(i) Weighing in motion :

The maximum permissible errors for weighing-in-motion shall be as specified in Table I

TABLE I

Accuracy class
Percentage of mass of single wagon or total train as appropriate
Verification

Inspection

0.2
±0.10%
±0.2%
0.5
±0.25%
±0.5%
1
±0.50%
±1.0%
2
±1.00%
±2.0%

................................................................................................
..............

Note: For the application of maximum permissible errors refer to paragraphs 2(8)(ii)(a) and 2(8)(ii)(b) of this part.

On initial verification of an instrument weighing coupled wagons, the errors of not more than 10% of the weighing results taken from one or more passes of the test train may exceed the appropriate maximum permissible error given in Table I but shall not exceed two time that value.

(a) A minimum of 500 metre rail track length shall be available with a gradient of not more than 1 : 400 on either side of automatic rail weighbridge.

2(2)(ii) Static weighing : The maximum permissible errors on static weighing for increasing or decreasing loads shall be the appropriate values in Table II.

TABLE II

Maximum permissible errors
Load (m) expressed in number of scale intervals
±0.5 d

0 m 500

±1.0 d
500 m 2000
±1.5 d
2000 m 10000

................................................................................................
..............

2(3) Scale interval (d)

For a particular method of weighing-in-motion and combination of load receptors, all weight indicating and printing devices on an instrument shall have the same scale interval.

The relationship between the accuracy class, the scale interval and the maximum wagon weight divided by the scale interval shall be as specified in Table III.

TABLE III

Accuracy class
d(kg)
(Maximum wagon weight)/d
minimum

maximum

0.2
50
1000
5000
0.5
100
500
2500
1
200
250
1250
2
500
100
600

The scale intervals of the indicating or printing devices shall be in the form of 1 x 10k, 2 x 10k, or 5 x 10k, “k” being a positive or a negative whole number or zero.

2(4) Minimum capacity

The minimum capacity shall not be less than 1t, and not greater than the value of the result of the minimum wagon weight divided by the number of partial weighings.

2(5) Minimum wagon weight

The minimum wagon weight shall not be less than 50d.

2(6) Single axle or bogie weights

Single axle or bogie weights shall not be indicated or printed without an associated warning that these weighing results cannot be verified.

2(7) Agreement between indicating & printing devics.

For the same load, the difference between the weighing results provided by any two devices having the same scale intervals shall be as follows:—

- zero for digital devices

- not greater than the absolute value of the maximum permissible error for weighing in motion for analog devices.

2(8) Weighing test methods

The appropriate procedures are specified in paragraph 5(1) (pattern evaluation) 5(2) (initial verification) and 5(3) (inspection) of this part.

2(8)(i) Static weighing :

An instrument to be used as a control instrument shall meet the requirements of paragraph 2(8)(iii)(b) and paragraph 2(8)(i)(a) to 2(8)(i)(f) inclusive. The maximum permissible errors shall comply with Table II.

2(8)(i)(a) Multiple load receptors :

Each load receptor shall be tested by the static-weighing method both independently and in combination.

2(8)(i)(b) Zero-setting :

The instrument shall be capable of setting to zero within ± 0.25% of the scale interval for a stationary load.

2(8)(i)(c) Eccentric loading :

The indications for different positions of the load shall comply with the maximum permissible errors for the given load.

2(8)(i)(d) Verification standards :

The error of the standard weights or masses used shall not be greater than one-third of the maximum permissible error for the load, as specified in Table II.

2(8)(i)(e) Test loads

2(8)(i)(e-i) Load at which errors are to be determined

Errors shall be determined for test loads of:

- zero

- minimum capacity,

- maximum capacity, and at or near a load where the maximum   permissible error changes

2(8)(i)(e-ii) Distribution of test load

Except for eccentricity test, standard weights or masses shall be evenly distributed on the load receptor.

2(8)(i)(e-iii) Eccentricity tests :

Tests shall be carried out without excessive stacking or overlapping of the load on the load receptor provided that the conditions are practical and safe. The test load shall be equal to one half of the maximum capacity rounded up to the next 1 tonne increment. The test load shall be on the rails covering the least area as is practicable and stacked across each pair of supports of the load receptor.

2(8)(i)(f) Discrimination tests :

An additional load that is equal to 1.4 times the scale interval for a stationary load, when gently placed on or withdrawn from each load receptor in turn when at equilibrium at any load shall change the initial indication.

2(8)(ii) Weighing-in-motion

2(8)(ii)(a) Wagon weighing :

The maximum permissible error for coupled or uncoupled wagon weighing shall be one of the following values, whichever is greater:

- the value calculated according to Table I, rounded to the nearest scale interval.

- the value calculated according to Table I, rounded to the nearest scale interval for the weight of a single wagon equal to 35% of the maximum wagon weight (as inscribed on the descriptive markings), or

- 1d.

2(8)(ii)(b) Train weighing :

The maximum permissible error for train weighing shall be one of the following values, whichever is greater:

- the value calculated according to Table I, rounded to the nearest scale interval,

- the value calculated according to Table I, for the weight of a single wagon equal to 35% of the maximum wagon weight (as inscribed on the descriptive markings) multiplied by the number of reference wagons in the train (not exceeding 10 wagons) and rounded to the nearest scale interval, or

- 1d for each wagon in the train but not exceeding 10d

See Figure 1 for an illustration of this requirement.

2(8)(iii) Verification standard

2(8)(iii)(a) Separate control instrument :

A control instrument capable of being used to determine the mass of each reference wagon when stationary and uncoupled shall be available for in-motion tests. The error of that instrument shall not be greater than either of the following values:—

- one-third of the appropriate maximum permissible error for in-motion-weighing in clause paragraph 2(8)(ii) of this part and Table I if the control instrument is verified immediately prior to the in-motion tests.

- one-fifth of the maximum permissible error if the control instrument is verified at any other time.

Figure I
AUTOMATIC RAIL-WELGHBRIDGES
Illustration of maximum permissible errors and in-motion test requirements for a sample train

An instrument constructed only for partial weighing of two axle wagons may be used as the control instrument provided that the alignment calibration in Annex B has been successfully applied.

2(8)(iii)(b) Integral control instrument

An instrument under test may be used as the control instrument provided that it meets the following requirements:—

- it must have an appropriate scale interval or scale interval for stationary land, and

- it must comply with the requirements in paragraph 2(8)(i) and para 2(8)(iii)(a) of this part.

An instrument constructed only for partial weighing of two-axle wagons may be used as the control instrument provided that the alignment calibration in Annex B has been successfully applied.

2(9) Influence quantities

2(9)(i) Temperature :

Instruments shall comply with the appropriate metrological and technical requirements at temperatures from - 10oC to + 45oC.

For special applications, however, the limits of the temperature range may differ provided that this range shall not be less than 30oC and shall be specified in the descriptive markings.

Instruments shall be tested in accordance with the static temperature tests in paragraph 8(1) of Annexure A.

2(9)(ii) Main Power Supply (AC) :

Instruments that are powered by an AC supply shall comply with the appropriate metrological and technical requirements when operated under variations of voltage from - 15% to + 10% of the value marked on the instruments.

Instruments shall be tested in accordance with main power supply (AC) test in paragraph 8(3) of Annexure A.

2(9)(iii) Battery Power supply (DC) :

Instruments that are powered by a DC supply shall, comply with appropriate metrological paragraph and technical requirements in accordance with paragraph 4(3)(viii) of this part.

Instruments shall be tested in accordance with the DC power supply test in paragraph 8(4) of Annexure A.

2(10) Conditions of use

2(10)(i) Use as a non-automatic weighing instrument :

An instrument that can be used as a non-automatic weighing instrument shall meet the requirements for accuracy class III (medium accuracy) and IIII (ordinary accuracy) under specification for “non-automatic weighing instruments” given in Heading A of the Seventh Schedule.

2(10)(ii) Scale interval for stationary load :

If the scale interval for stationary load is not equal to the verification scale interval (d), it shall be automatically out of service when the instrument is in use for weighing-in-motion. In addition, if the instrument is not verified for use as a non-automatic weighing instrument, the verification scale interval for stationary load shall not be readily accessible and shall only be used for static testing

3. Technical requirement

3(1) Composition :

Instruments shall include the following:

- one or more load receptors,

- aprons,

- vehicle type identification devices (e.g. track switch, load cells, transponder, etc.),

- indicating devices,

- printer,

- control unit.

3(2) Suitability for use :

Instrument shall be designed to suit the vehicle, site and method of operation for which they are intended.

Instruments constructed only for partial weighing shall not be used to weigh liquid loads or any other load that may be subjected to fluctuations in its gravity centre, unless there is a possibility to anticipate and compensate for such fluctuations.

3(3) Security of operation

3(3)(i) Accidental maladjustment:

Instruments shall be constructed so that maladjustments likely to disturb their metrological performance cannot normally take place without the effect being easily detected.

3(3)(ii) Interlocks :

Interlocks shall prevent the use of any control device that may alter a weighing operation.

3(3)(iii) Uncoupled wagon weighing :

Instruments used for uncoupled wagon weighing shall recognize and indicate the following situations:

- the passage of two or more coupled wagons,

- the passage of two or more uncoupled wagons that is sufficiently close to cause either a malfunction of the instruments or errors exceeding the appropriate maximum permissible errors.

3(3)(iv) Use as a non-automatic weighing instrument :

An instrument to be used as a non-automatic weighing instrument shall

- comply with the requirements of accuracy class III or class IIII of “specification for non-automatic weighing instruments prescribed in Seventh Schedule Heading A, and

- be equipped with an enabling device for non-automatic operation that prevents both automatic operation and in-motion weighing.

3(3)(v) Zero setting device :

An instrument shall be equipped with a semi-automatic or automatic zero setting device for each load receptor. Its operation shall be possible only when the instrument is in stable equilibrium and when the rate of correction is no more than 0.5d/s.

The range of the zero-setting device shall not exceed 4% of the maximum capacity.

3(4) Indicating and printing devices

3(4)(i) Quality of indication :

The weight indication shall be the self-indicating type. Indicating and printing device shall allow reliable, simple and unambiguous reading of the results by simple juxtaposition and shall bear the name or symbol of the appropriate unit of mass.

3(4)(ii) Printing :

The minimum printout resulting from each normal weighing operation shall be each wagon weight in the case of wagon weighing and total train weight in the case of train weighing.

3(4)(iii) Weighing range :

Instruments shall not indicate or print :

- the weight of any wagon, or

- a totalized weight inclusive of any wagon, that will cause a weighing results less than Min or grater than Max + 9d.

3(4)(iv) Operating speed :

The printer shall not print the weight or any wagon that has traveled over the load receptor at a speed outside the range of operating speeds. An appropriate indication shall be included on the printout for any wagon weight not printed and subtotal may be printed exclusive of unweighed wagons provided that an indication clearly specified that it is not the total train weight.

3(4)(v) Roll back :

The weight indication and printout shall not be altered due to any part of any wagon traveling over the load receptor more than once. If Rollback takes place at the time of testing the entire weighing operation has to be repeated a new. The speed difference shall not be more than 3 kmph.

3(5) Installation

3(5)(i) Ease of static testing :

The instrument shall be accessible to vehicle for moving test weights if it is to be used as the control instruments.

3(5)(ii) Drainage :

If the weighing mechanism is contained in a pit, there shall be a provision for drainage to ensure that no portion of the instrument becomes submerged or partially submerged in water or any other liquid.

3(6) Descriptive markings

Instruments shall bear the following basic markings at each location having a weight indicating or printing dervice.

3(6)(i) Markings shown in full

- identification mark of the manufacturer

- identification mark of the importer (if applicable)

- designations of the instrument

- serial number of the instrument on each load receptor (if applicable)

- weighing method (see item 3(1) under part I)

- maximum wagon weight-kg or t

- minimum wagon weight-kg or t

- not to be used to weigh liquid products (if applicable)

- full draught or number of partial weighing per wagon

- not to be used to weigh liquid product (if applicable)

- maximum transit speed-km/h

- direction of weighing (if applicable)

- wagons pushed/pulled (whichever is applicable)

- scale interval for stationary load (if applicable)-kg

- or t

- electric power supply voltage and frequency-v...... Hz

3(6)(ii) Marking shown in code

3(6)(ii)(a) For all instruments

- pattern approval mark

- accuracy class (for each weighing method, if applicable) 0.2, 0.5, 1 or 2.

- maximum capacity Max-kg or t

- minimum capacity Min-kg or t

- scale inter d-kg or t

- maximum operating speed V max-km/h

- minimum operating speed V min-km/h

3(6)(ii)(b) For coupled wagon and train weighing : Marking required for each weighing method applicable:

- maximum number of wagons per train -n max.

- minimum number of wagons per train -n min.

3(6)(iii) Other markings :

The designation of the liquid(s) which the instruments is designed to weight (if applicable)

3(6)(iv) Presentation of descriptive markings :

Descriptive markings shall be indelible and of a size, shape and clarity that permit legibility under normal conditions of ujse of the instrument

Markings shall be grouped together in a clearly visible place on the instrument, either on a descriptive plate fixed near the indicating device or on the indicating device itself

It shall be possible to seal the plate bearing the markings, unless it cannot be removed without being destroyed.

3(7) Verification marks

3(7)(i) Position :

Instruments shall have a place for the application of verification marks. The following applies for this place:

The part on which the marks are located cannot be removed from the instruments without damaging the marks.

The place shall permit the easy application of the marks without changing the metrological qualities of the instruments.

The marks shall be visible when the instrument is in service.

3(7)(ii) Mounting :

Instruments required to bear verification marks shall have a verification mark support located as specified above, which shall ensure the conservation of the marks as follows:—

- When the mark is made with a stamp, the support may consist of a strip of lead or any other material with similar qualities inserted into a plate fixed to the instrument or a cavity bored into the instrument.

- When the mark consists of an adhesive transfer, a space shall be provided for this purpose.

4. Requirements for electronic instruments

Electronic instruments shall comply with the following requirements, in addition to the applicable requirements of all other clauses.

4(1) General requirements

4(1)(i) Rated operating conditions :

Electronic weighing instruments shall be designed and manufactured so that they do not exceed the maximum permissible errors under rated operating conditions.

4(1)(ii) Disturbances :

Electronic instruments shall be designed and manufactured so that when they are exposed to disturbances, either

4(1)(ii)(a) significant faults do not occur, or

4(1)(ii)(b) significant faults are detected and acted upon.

Note: A fault equal to or less than the significant fault (1d) is allowed irrespective of the value of the error of indication.

4(1)(iii) Durability :

The requirements in paragraphs 4(1)(i) and 4(1)(ii) of this part shall be met durably in accordance with the intended use of the instrument

4(1)(iv) Evaluation for compliance :

A pattern of an elecronic instrument is presumed to comply with the requirements in paragraphs 4(1)(i), 4(1)(ii) and 4(1)(iii) of this part if it passes the examination and tests specified in Annexure A.

4(2) Application

4(2)(i) The requirements in paragraph 4(1)(ii) of this part may be applied separately for the following:—

each individual cause of significant fault, and/or

each part of the electronic instrument

4(2)(ii) The choice as to whether to apply paragraph 4(1)(ii)(a) or paragraph 4(1)(ii)(b) of this part is left to the manufacturer.

4(3) Functional requirements

4(3)(i) Acting upon a significant fault :

When a significant fault has been detected, a visual or audible indication shall be provided and shall continue until the user takes action or the fault disappears.

Means shall be provided to retain any totalized load information contained in the instrument when a significant fault occurs.

4(3)(ii) Switch-on procedure :

Upon switch-on (in the case of electronic instruments permanently connected to the mains at switch-on of indication), a special procedure shall be performed that indicates all the relevant signs of the indicator in their active and non-active state for a sufficient time to be easily observed by the operator.

4(3)(iii) Influence factors :

An electronic instrument shall comply with the requirements of paragraph 2(9) of this part and in addition it shall maintain its metrological and technical characteristics at a relative humidity of 85% at the upper limit of the temperature range of the instrument.

4(3)(iv) Disturbances :

When an electronic instrument is subjected to the disturbances specified in Annex A, either of the following shall apply:

The difference between the weight indication due to the disturbance and the indication without the disturbances (instrinsic error) shall not exceed the significant fault (1d).

The instrument shall detect and act upon a significant fault.

4(3)(v) Warm up time :

During the warm-up time of an electronic insrument, there shall be no indication or transmission of the weighing result and automatic operation shall be inhibited.

4(3)(vi) Interface :

An instrument may be equipped with an interface permitting the coupling of the instrument to external equipment. When an interface is used, the instrument shall continue to function correctly and its metrological functions shall not be influenced.

4(3)(vii) Mains power supply (AC) :

An instrument that operates from the mains shall in the event of a power failure retain the metrological information contained in the instrument at the time of failure for at least 24 hours. A switch-over to an emergency power supply shall not cause a significant fault.

4(3)(viii) Battery power supply (DC) :

An instrument that operates from a battery power supply shall, whenever the voltage drops below the manufacturer's specified value, either continue to function correctly or automatically be put out of service.

4(4) Examination and tests :

The examination and testing of an electronic weighing instrument is intended to verify compliance with the applicable requirements of this specification and especially with the requirements in paragraph 4 of this part.

4(4)(i) Examinations :

An electronic weighing instrument shall be examined to obtain a general appraisal of the design and construction.

4(4)(ii) Performance tests :

An electronic weighing instrument or electronic device, as appropriate, shall be tested as specified in the Annex to determine their correct functioning.

Tests are to be conducted on the whole instrument except when the size and/or configuration of the instrument does not lend itself to testing as a unit. It such cases, the separate electronic devices shall be subjected to testing. It is not intended that electronic devices be further dismantled for separate testing of components. In addition, an examination shall be carried out on the fully operational weighing instrument or, if necessary, on the electronic devices in a simulated set-up that sufficiently represents the weighing instrument. The equipment shall continue to function correctly as specified in Annexure A.

4(4)(iii) Span stability tests :

The instrument shall be subjected to span stability tests at various intervals, before during and after being subjected to performance tests.

When the instrument is subjected to the span stability tests specified in paragraph 10 of Annexure A.

The maximum allowable variation in the errors of indication shall not exceed half the absolute value of the maximum permissible error in Table II for the test load applied on any of the n measurements.

Where the difference of the results indicate a trend more than half the allowable variation specified above, the test shall be continued until the trend comes to rest or reverses itself, or until the error exceeds the maximum allowable variation.

5. Metrological controls

The metrological controls of instruments shall consist of the following:—

- pattern evaluation

- initial verification

- in-service inspection

5(1) Pattern evaluation

5(1)(i) Documentation :

The application for pattern evaluation shall include documentation which provides the following information:—

- metrological characteristics of the instrument;

- a standard set of specifications for the instruments;

- a functional description of the components and devices;

- drawings, diagrams and general soft ware information (if applicable), explaining the construction and operation;

- any document or other evidence demonstrating that the design and construction of the instrument complies with the requirements of this specification.

5(1)(ii) General Requirements :

Pattern evaluation shall be carried out on at least one and normally, not more than three instruments that represent the definitive pattern. At least one of the instruments shall be completely installed at a typical site and at least one of the instruments or the major component of an instrument shall be submitted in a form suitable for simulation testing in a laboratory. Pattern evaluation shall be carried out as prescribed under the Model Approval Rules.

The evaluation shall consist of the tests specified in paragraph 5(1)(iii) of this part.

5(1)(iii) Pattern evaluation tests :

Instruments shall comply with the following:—

- the metrological requirements in paragraph 2 of this part, particularly with reference to maximum permissible errors and, if appropriate, when the instrument is operated in accordance dwith the manufacturer's specification for products;

Note: Evaluation for static weighing [paragraph 2(8)(i)] shall be excluded unless the instrument is constructed for use as a control instruments [paragraph 2(8)(iii)(b)].

- the technical requirement in paragraph 3 of this part.

Additionally, electronic instruments shall comply with the requirements in paragraph 4 ofthis part.

5(1)(iii)(a) In-motion tests :

The instrument shall be tested in accordance with the provisions in paragrapph 2(8)(ii) of this part by reference to “initial verification” as apparopriate and shall comply with the requirements in paragraph 2(7) of this part. Errors shall be determined by comparing the tests results with the reference wagon mass derived as in paragraph 2(8)(iii) of this part.

The range of speeds used during these tests shall be in accordance with the pattern specification.

5(1)(iii)(a-I) Uncoupled wagons :

Instruments for weighing individual un coupled wagons shall be tested using not less than five reference wagons having a range of loads from zero load (wagon tare weight) to that of a fully loaded wagon. A minimum of five weight indications or print outs of each wagon shall be used for assessing compliance with the requirements in paragraph 2(8)(ii)(a) of this part.

5(1)(iii)(a-II) Couplied wagons :

Instruments designed to weigh either individual coupled wagons or a total train of coupled wagons shall be tested in either of the following manners:—

- By using a test train of empty reference wagons and a test train of both full and partially filled reference wagons. Each test train shall be comprised of not less than five (and normally not more than 15) reference wagons and shall be weighed repeatedly and in each direction (if applicable) to yield not less than 60 wagon weights or the equivalent in total train weight.

- According to the requirements in paragraph 5(2)(ii) of this part.

- Each weight indication and printout obtained in the test shall be used for assessing compliance with requirements in either paragraphs 2(8)(ii)(a) or 2(8)(ii)(b) of this part, as appropriate:

PROVIDED that where test wagons are not available loaded wagon weighed on a static machine fulfilling conditions laid down in paragraph 2(8)(i)(d) of this part shall be used as a reference wagon.

5(1)(iii)(b) Simulation tests :

Influence factors shall be applied during simulation tests in a manner that will reveal an alteration of the weighing results for any weighing process to which the