Electricity and Gas Inspection Regulations

40 For the purpose of paragraph 35(e),

• (a) subject to paragraphs (b) and (c), the supercompressibility factor for any meter shall be established based on

  • (i) the pressure exerted by the gas within the meter and the temperature of the gas flowing through the meter as determined by continuous monitoring at the meter location,

  • (ii) the relative density, the carbon dioxide content and the nitrogen content of the gas being measured, as determined by

    • (A) a gas sampling process, if the process gives results that are representative of the gas at the meter location, or

    • (B) continuous monitoring at the meter location, and

  • (iii) if the parameters of the gas referred to in subparagraphs (i) and (ii) vary, either the time weighted or the volume weighted averages of those parameters during the period that the volume of the gas is measured by the meter;

• (b) the supercompressibility factor for any meter for which the pressure exerted by the gas within the meter expressed on the gauge pressure scale does not exceed 207 kPa in the International system of units, or 30 psi in the Imperial system of units, may be established based on

  • (i) the pressure exerted by the gas within the meter, established and maintained through the use of a pressure factor metering regulator that has been approved and verified under section 9 of the Act,

  • (ii) an assumed flowing gas temperature of 59°F or 15°C, and

  • (iii) the relative density, the carbon dioxide content and the nitrogen content of the gas being measured as determined by a gas sampling process, if the process gives results that are representative of the gas at the meter location; or

• (c) a supercompressibility factor of one may be used if the pressure exerted by the gas within the meter expressed on the gauge pressure scale does not exceed 700 kPa in the International system of units or 100 psi in the Imperial system of units.