SECTION 165:45-5-11. Place and methods for meters and test equipment

(a)   Domestic meters-diaphragm type (under 500 c.f.h. capacity).

(1)   All tests on domestic meters in service, provided for in this Chapter, shall be made at an approved testing facility with a suitable meter prover as specified in OAC 165:45-5-10. The differential pressure carried on the prover shall not exceed two inches (2") of water column pressure.

(2)   Meters shall be tested at two or more rates of flow as needed to ascertain their accuracy. When two rates are used, the low flow rate shall be equivalent to 20% to 40% of the applicable badged capacity and the high flow rate shall be equivalent to 80% to 120% of the applicable badged capacity (See ANSI B109.1 Section 4.2.4). Before being placed in service, meters shall be adjusted to an accuracy of 100% within the limits of plus or minus one (1) percent at a low flow rate (20% to 40% of capacity) and a high flow rate (80% to 120% of capacity). The numerical difference between the test values for these two rates should not exceed one (1) percentage point.

(b)   Special meters-diaphragm type (500 c.f.h. or more capacity).

(1)   All tests on large positive meters in service provided for in this Chapter shall be made with approved testing apparatus as specified in OAC 165:45-5-10. Such meters shall be tested on location on the consumer's premises, if feasible. Meters shall be tested with air at one or more rates of flow as needed to ascertain their accuracy. When two rates are used, the low flow rate shall be equivalent to 20% to 40% of the applicable meter capacity and the high flow rate shall be equivalent to 80% to 120% of the applicable meter capacity. These tests shall be conducted on the basis of either the 0.5 or 2 inch water column (125 or 500 Pa) capacity of the meter as appropriate for its use. (See ANSI B109.2 Section 4.2.4). Before being placed in service, meters shall be adjusted to an accuracy of 100% within limits of plus or minus one percent at low flow (20% to 40% of capacity) and a high flow rate (80% to 120% of capacity). The numerical difference between the test values for those two rates should not exceed one percentage point.

(2)   All tests on orifice meters in service provided for in this Chapter shall be made in their permanent location on the consumer's premises with approved testing apparatus as specified in OAC 165:45-5-10. The accuracy of the differential pressure registration shall be determined on a rising and falling pressure throughout the entire range of the differential element. The accuracy of the static pressure registration shall be determined at zero or atmospheric pressure and at least a second point which approximates the normal operating pressure of the recorder.

(c)   Rotary type meters. Rotary meters shall be tested and calibrated at the factory and/or the utility's meter shop in accordance with recognized and accepted practices, and shall be correct to within plus or minus one percent when operating at rated capacity. Meter accuracy shall be 100% plus or minus one percent from approximately 20% to 100% of the meter's rated capacity (See ANSI B109.3 Section 4.2.3.). Rotary meters may be tested and calibrated on location or at the utility's facilities with an approved apparatus as specified in OAC 165:45-5-10. Meters shall be tested at one or more rates of flow to ascertain their accuracy. When one rate of flow is used, it shall be 10% to 30% of the rated capacity. When two rates are used, one of the flow rates shall be the same as the single test. The high flow rate shall be 60% to 100% of the rated capacity. If this is not attainable, then it shall be the maximum capacity of the proving equipment. If an intermediate flow rate is used, it should be approximately midway between the low and high rates. After the initial accuracy tests have been made by the manufacturer or user, differential tests may be used to confirm the continued accuracy of in-service rotary meters (See ANSI B109.3 Section 4.2.2.).

(d)   Turbine meters. Turbine meters shall be tested and calibrated at the factory and/or the utility's meter shop in accordance with recognized and accepted practices and shall be correct to within plus or minus one (1) percent when operating at rated capacity (See American Gas Association Report No. 7 Sections 8 and 9). Turbine meters may be tested and calibrated on location or at the utility's facilities with an approved testing apparatus as specified in OAC 165:45-5-10.

[Source: Amended at 13 Ok Reg 3259, eff 7-25-96; Amended at 36 Ok Reg 668, eff 7-25-19]