Section 31.31.01.153 - METER PROVING01.Meter Provers. Each gas corporation shall own at least one (1) meter prover of a type approved by the Commission and shall maintain such equipment in proper adjustment and so calibrated that the error of indication shall not exceed one-half percent. No meter prover shall be so placed as to subject it to excessive temperature variation and each meter prover shall be equipped with suitable thermometers and other necessary accessories. Additional meter proving station shall be installed when and where found necessary by the Commission.02.Testing Apparatus for Large Capacity Meters. Each gas utility using orifice meters, high pressure meters, proportional meters, or other large capacity meters shall own and maintain testing apparatus of a type approved by the Commission.03.Accuracy of Meter Provers and Testers. The accuracy of all provers and methods of operation may be established from time to time by a representative of the Commission. Any alterations, accidents, or repairs that might affect the accuracy of any meter prover, or the method of operating it, shall be promptly reported in writing to the Commission.Idaho Admin. Code r. 31.31.01.153