The Gas (Meters) Regulations 1983

Prescribed standards for meters

3.—(1) The standards with which a meter examiner is to be satisfied that a meter conforms so that he may stamp, or authorise the stamping of, the meter in accordance with section 30(2) of the Act are as follows:—

(a) the meter is such that no gas or air will escape from it;

(b) in the case of any diaphragm meter, the meter, when used for the purpose of ascertaining the quantity of either gas or air passing through it—

(i) at any rate of flow not less than 1/50th of the greatest rate of flow for which it is designed and not more than that greatest rate of flow, will register such quantity of gas or air as does not differ from the actual quantity of gas or air passing through the meter by more than 2 per cent of that actual quantity; and

(ii) at the rate of flow specified in column 1 of Table A below which corresponds to the greatest rate of flow for which it is designed specified in column 2 of the Table, will register the passage of gas or air;

Table A

Column 1	Column 2
Rate of flow in cubic decimetres per hour	Greatest rate of flow for which the meter is designed in cubic metres per hour
15	Not exceeding 6
30	Exceeding 6 but not exceeding 25
60	Exceeding 25 but not exceeding 65
150	Exceeding 65

(c) in the case of a meter other than a diaphragm meter, the meter, when used for the purpose of ascertaining the quantity of either gas or air passing through it—

(i) at any rate of flow not less than 1/5th of the greatest rate of flow for which it is designed and not more than that greatest rate of flow, will register such quantity of gas or air as does not differ from the actual quantity of gas or air passing through the meter by more than 1 per cent of that actual quantity; and

(ii) at any rate of flow not less than the smallest rate of flow for which it is designed and less than 1/5th of the greatest rate of flow for which it is designed, will register such quantity of gas or air as does not differ from the actual quantity of gas or air passing through the meter by more than 2 per cent of that actual quantity;

(d) in the case of a diaphragm meter designed to operate at a pressure of not more than 1 bar, the mean difference between the pressure of air at the inlet of the meter and the pressure of air at the outlet of the meter, where air is passing through the meter at the greatest rate of flow for which it is designed, will not exceed the amount specified in column 1 of Table B below which corresponds to that greatest rate of flow specified in column 2 of the Table; and

Table B

Column 1	Column 2
Mean difference in millibars	Greatest rate of flow for which the meter is designed in cubic metres per hour
2.0	Not exceeding 16
3.0	Exceeding 16 but not exceeding 65
4.0	Exceeding 65

(e) in the case of any diaphragm meter, the difference between the pressure at the inlet of the meter and the pressure at the outlet of the meter, when air is passing through the meter at the rate of flow which is 1 per cent of the greatest rate of flow for which the meter is designed, will not exceed the amount specified in column 1 of Table C below which corresponds to that greatest rate of flow specified in column 2 of the Table.

Table C

Column 1	Column 2
Mean difference in millibars	Greatest rate of flow for which the meter is designed in cubic metres per hour
0.6	Not exceeding 65
1.0	Exceeding 65

(2) A meter shall be deemed to conform with a standard prescribed by paragraph (1)(b) or (c) above, notwithstanding that gas instead of air is passing through the meter, where the results of testing for that standard show that if it had been conducted with air passing through the meter—

(a) at a density of 1.2 kilograms per cubic metre, or

(b) in a case where the meter is marked in such manner as is approved by the Secretary of State so as to indicate that the meter is to be used only for the purpose of ascertaining the quantity of gas supplied to any person at a specified range of densities of which the lower limit exceeds 1.2 kilograms per cubic metre, at the higher and lower limits of that range,

the meter would have conformed with that standard.

(3) A meter shall be deemed to conform with a standard prescribed by paragraph (1)(d) or (e) above, notwithstanding that gas instead of air is passing through the meter, where the results of testing for that standard show that, if it had been conducted with air passing through the meter at a density of 1.2 kilograms per cubic metre, the meter would have conformed with that standard.