Customer Use. All gas sold by a utility shall be on the basis of meter measurement, except for installations where the usage is constant and the consumption may readily be computed, or as provided for in its filed rates. Utility Use. Wherever practicable, consumption of gas within the utility itself, or by administrative units associated with it, shall be metered, except for installations where the usage is constant and the consumption may readily be computed. Meters. Before any meter may be installed for use for revenue billing purposes, the type and design of the meter shall be approved by the Commission. Correcting Devices. Before any pressure or temperature device may be used for the purpose of correcting the registration of a meter, the type and design of the device or devices shall be approved by the Commission. Testing Equipment. Before any type of prover or other item of testing equipment may be used to test meters and associated devices, the type and design of the provers or testing equipment shall be approved by the Commission. Condition. A meter may not be installed if it is mechanically defective, has incorrect constants, or has not been tested, and adjusted if necessary. Capacity. The capacity of the metering installation and the index mechanism should be consistent with the gas requirements of the customer. If it is necessary to apply a multiplier such as 10, 100, 1000, etc. to a meter reading to obtain the actual consumption, the information shall be shown on the face of the meter register. Meters shall be read at approximate monthly intervals, unless otherwise authorized by the Commission. The meter reading sheets, cards, or records from which bills are prepared shall show: Customer's name, address, and rate schedule; Identifying number or description of the meter; Meter readings; Date of meter reading; If the reading has been estimated; Any applicable fixed multiplier or constant. Each utility shall maintain records of each meter and associated metering device which will identify each item as to its design, capacity, and application. The identifying information may include, as applicable: manufacturer, number, type, capacity, multiplier, constants, pressure rating, and compensated index with associated pressure. Each utility shall maintain records for each meter and associated metering device, which shall show, as applicable, the date of installation, the date of removal from service, and the location at the present address. Each utility shall maintain the latest test records for each meter which shall include the following: The date and reason for the test; The reading of the meter before making any test; The proof “as found” at check flow; The proof “as left” at check and full rated flow; and If a test of the meter is made by using a working standard other than a bell prover, the utility shall retain all data taken at the time of the test in sufficiently complete form to permit the convenient checking of the test methods and the calculations. Public Utilities Article, §§2-121, 5-101, and 7-301, Annotated Code of Maryland Effective date: July 1, 1964 (Order No. 55567) Chapter revised effective October 21, 1974 (Order No. 60922) Regulation .06F amended effective February 7, 2000 (27:2 Md. R. 146)