Legal Metrology Act, 2014 (Act No. 9 of 2014)RegulationsLegal Metrology Regulations, 2017Part XI : Measuring instruments and containers used for prescribed purposes106. Liquid-measuring devices |
| (1) | A liquid-measuring device must be designed to determine the quantity of liquid to be delivered and to repeat such determination indefinitely, without the quantity requiring to be reset, provided that provision may be made for the predetermination by an operator of various quantities to be delivered. |
| (2) |
| (a) | A liquid-measuring device must have its measuring capacity and the number of the certificate of approval of the model, marked on the body of the liquid-measuring device or on a metal plate permanently affixed thereto; provided that, in the case of a liquid-measuring device which incorporates a transparent measuring chamber or chambers, the capacity of each such chamber must be conspicuously marked thereon or in close proximity thereto so that it is visible during use and such measuring chamber must not bear any legend other than the said capacity marking, and the number of the certificate of approval of the model if not marked near the indication of the measuring capacity of the instrument. |
| (b) | Where provision is made on a liquid-measuring device for the predetermination of various quantities to be delivered, such predetermination must be clearly defined on the liquid-measuring device and the denomination of such quantities must be clearly marked. |
| (3) | A liquid-measuring device must be so constructed that— |
| (a) | there is no leakage at any point, especially at any joints, glands and sight glasses, where the latter are provided; |
| (b) | the formation of air pockets is prevented; |
| (c) | all valves are effective for their purpose and, where gland nuts are provided,such nuts must not require to be tightened to an extent which makes valve operation difficult; and |
| (d) | means are provided for sealing any calibrating or volume adjusting mechanism. |
| (4) |
| (a) | Where a liquid-measuring device is provided with a measuring chamber which is alternately filled and emptied, adequate means must be provided for the expulsion of air from the chamber while it is being filled and for admission of air thereto while it is being emptied. |
| (b) | Where measurement by a liquid-measuring device is effected by means of a piston moving in a measuring chamber or chambers, such piston and chamber must not comprise the pump for drawing the liquid into the chamber. |
| (5) |
| (a) | A liquid-measuring device which measures a quantity of liquid by inference from the pressure on the liquid flowing through an orifice and the time for which the liquid flows through such orifice must be provided with means for maintaining such pressure and time at levels which ensure the delivery of the correct quantity. |
| (b) | Where a liquid-measuring device referred to in paragraph (a) is provided with a nozzle which remains filled at the end of a delivery, such nozzle must be of a "non-drip" type and the outlet must be protected so as to prevent draining of such nozzle. |
| (6) |
| (a) | Where liquid-measuring devices are fitted with electronic components that may affect their metrological integrity such components must be designed such that they are not susceptible to environmental influences and if failure occurs, the liquid-measuring device either stops operating or the metrological integrity including any primary or supplementary indication is not affected. |
| (b) | The type approval authority shall decide, in consultation with the submitter for type approval, on any additional tests of electronic components that may be required. |
| (7) | Where the supply of liquid for a liquid-measuring device is not visible to an operator or where such measuring instrument is not provided with a transparent measuring chamber or chambers, means must be provided for informing the operator when the supply of liquid is below the minimum level required for accurate measurement. |
| (8) | Where a liquid-measuring device is provided with a totalizer, the figures of such totalizer must be clearly legible and where provision is made for resetting such totalizer, the figures must be properly aligned when the totalizer is set to zero. |
| (9) | A liquid-measuring device must be installed and operated in such manner as to deliver the correct volumes. |
| (10) |
| (a) | As far as is practicable, the liquid which is normally measured by a liquid-measuring device must be used for testing the liquid-measuring device. |
| (b) | After the liquid-measuring device and any delivery hose or pipe attached thereto have been thoroughly flushed, each separate measuring chamber or measurement unit must be tested for accuracy and constancy of delivery by allowing the liquid to flow from the liquid-measuring device directly into an appropriate measurement standard of volume that comply with the requirements in Part III of these regulations: Provided that, where the capacity of the liquid-measuring device or some other factor precludes the method of direct comparison with a measure of volume, the net mass of the liquid delivered must be determined by means of a weighing instrument that comply with the requirements in Part III of these Regulations and such net mass must be converted to measure of volume on the basis of the density of the liquid. |
| (c) | Where a liquid-measuring device provides for the delivery of various predetermined quantities, each such quantity or as many such quantities as considered necessary must be tested. |
| (d) | Tests of a liquid-measuring device must be repeated a sufficient number of times to provide reliable data. |
| (e) | These tests must be carried out at ambient conditions. |
| (11) | Error must be allowed on liquid-measuring devices, when new, repaired or in trade use, in accordance with Table 18 and Table 19. |
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2 |
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TABLE 18 |
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Quantity delivered |
Error allowed in excess or in deficiency |
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Up to 10 mL |
0,4 mL |
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Over 10 mL and up to 20 mL |
4% |
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Over 20 mL and up to 30 mL |
0,8 mL |
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Over 30 mL and up to 50 mL |
3% |
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Over 50 mL and up to 60 mL |
1,5 mL |
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Over 60 mL and up to 200 mL |
2,5% |
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Over 200 mL and up to 250 mL |
5 mL |
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Over 250 mL and up to 500 mL |
2% |
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Over 500 mL and up to 700 mL |
10 mL |
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Over 700 mL and up to 20 mL |
1,5% |
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Over 1 L and up to 1,5 L |
15 mL |
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Over 1,5 L and up to 2 L |
1% |
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Over 2 L and up to 3 L |
20 mL |
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Over 3 L and up to 5 L |
0,7% |
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Over 5 L and up to 6 L |
35 mL |
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Over 6 L and up to 10 L |
0,6% |
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Over 10 L and up to 12 L |
60 mL |
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Over 12 L and up to 50 L |
0,5% |
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Over 50 L and up to 100 L |
250 mL |
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Over 100 L |
0,25% |
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1 |
2 |
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TABLE 19 |
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Quantity delivered |
Error allowed in excess only |
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25 mL |
1,25 mL |
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50 mL |
2,5 mL |
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| (12) |
| (a) | The verification mark must be applied in one of the following ways as prescribed in type approval documentation: |
| (i) | By means of a stamp on a lead plug inserted into a conspicuous, easily accessible and essential part of the liquid-measuring device and, in the case of a liquid-measuring device provided with metal displacers for altering the volume of the measuring chambers, the verification mark shall be placed upon the displacers unless they can be sealed in position. If necessary to protect delicate liquid-measuring devices when stamping the verification mark it is permissible to replace the lead with sealing wax and to apply the mark to the melted wax; |
| (ii) | by means of a verification sticker applied to a conspicuous part of the liquidmeasuring device without obscuring any of the required markings or the view of the liquid in a transparent measuring chamber. Such sticker shall not be removable without destruction; |
| (iii) | by means of imprinting the verification mark on a lead seal secured to the body of the liquid-measuring device by inserting sealing wire through a hole in the body in a conspicuous position that does not interfere with the metrological integrity of the liquid-measuring device; or |
| (iv) | the reverse of one of the seals required in subparagraph (b) may also be used to apply the verification mark. |
| (b) | Seals must be affixed to the liquid-measuring device to prevent unauthorised adjustment or access to the working parts or measuring chambers, except as otherwise provided in terms any additional requirements that may have been set at the time of type approval. |