(A) The unit of measure to be employed by the inspector in making the test of meters herein provided for, shall be the cubic foot containing 62.321 pounds of rain or distilled water, as a temperature of 62°F, and at a barometric pressure of 30 inches.
(B) All meters shall be tested at a pressure which will balance a column of water l/2-inch in height and the accuracy of the meter shall be determined by the use of standard provers designated and constructed for the purpose.
(C) There shall be maintained in the office of the Sealer of Weights and Measures at least 1 standard gas meter which has been tested, sealed and certified by the United States Bureau of Standards. The meter so maintained shall be used as standard for the purpose of checking and testing meters used by consumers of gas.
(Prior Code, § 50.18)