(a) Each utility shall maintain the equipment and facilities necessary for accurately testing all types and sizes of meters employed for the measurement of gas to its customers, unless the department finds that alternate arrangements made to have such testing done elsewhere will provide equivalent protections to customers.
(b) Meter provers used by the utility or its agent for the testing of meters shall be of a type recommended by the manufacturer and of a capacity of not less than 5 cubic feet.
(c) Each meter prover shall be supplied with accessories needed for accurate meter testing and shall be located in a room suitable for the work to be done.
(d) The utility shall maintain, or cause to have maintained on its behalf, the meter prover in good condition and correct adjustment so that it can determine the accuracy of any gas meter to within 1/2 of one percent.