These test periods may be extended upon application and approved by the commission, providing that the gas utility can prove by its own records that different test periods are adequate for the protection of the public. Meters may be tested and calibrated in accordance with “Sample Meter Testing Plans” approved by the commission; and gas utilities using a “Sample Meter Testing Plan” shall continue to advise the commission of the results of the operation of the plan.

1. a. Positive Displacement Meters.

   1. (1) Up to 251 c.f./hr. (at .5 in. water column differential pressure with non-absorptive diaphragm)-Ten years.
   2. (2) 251 to 3000 c.f./hr (at .5 in. water column differential pressure)-Three years.

   3. (3) Over 3000 c.f./hr. (at .5 in. water column differential pressure)-Two years.

      b.	Orifice Meters.	Six Months.
      c.	Turbine Meters.	Six Months.
      d.	Base Pressure Correcting Devices.	Two Years.
      e.	Base Volume Correcting Devices.	Two Years.
      f.	Recording Pressure and Temperature Gauges.	One Year.
      g.	Secondary Standards.
      	(1)	Test Bottles, one cubic foot	Five Years.
      	(2)	Dead Weight Testers including Weights	Five Years.
      h.	Working Standards.
      	(1)	Bell Provers	Five Years.
      	(2)	Flow Provers	Five Years.
      	(3)	Transfer Provers	Five Years.
      	(4)	Laboratory Quality Indicating Pressure Gauges	Six Months.
      	(5)	Laboratory Quality Thermometers	Six Months.

HISTORY: Amended by State Register Volume 14, Issue No. 3, eff March 23, 1990; State Register Volume 32, Issue No. 5, eff May 23, 2008.