(1) Electric utilities must use electric meters or other such devices to accurately record or indicate the quantity of electricity sold to customers. Such measuring devices will allow utilities to calculate a customer's consumption in units of kilowatt hours or other units as filed in the company's tariffs.

(2) Electric utilities that decide to either measure a customer's consumption with a device that employs a multiplier or calculate consumption from recording devices must provide customers, upon request, information sufficient to enable the customer to compute the quantity consumed.

(3) Indirect reading meters and those that operate from instrument transformers must have the multiplier plainly marked on the dial of the instrument or be otherwise suitably marked.

(4) The watt-hour constant for the meter itself must be placed on all watt-hour meters (as specified in ANSI C12.1). Information about the ANSI C12.1 regarding the version adopted and where to obtain it is set out in WAC 480-100-999 Adoption by reference.

(5) Measuring devices that have the capability to do so must measure all energy sold to customers at a minimum of sixty-minute intervals for residential customers and fifteen-minute intervals for nonresidential customers.