scope:

This Standard specifies the normal watt-hour meters for general use, that are independently used without combining with an instrument transformer in single-phase tow-wire system, single-phase three-wire system, three-phase three-wire system and three-phase four-wire system circuits (type III single-element direct-connection type meters and Type III multi-element direct connection type meters) (hereafter referred to as "meters").

In addition, the transmitter of a watt-hour meter (for direct connection) for centralized and automatic meter reading shall be in accordance with Annex A. Furthermore, for the meters equipped with auxiliary devices, this Standard shall he applied to the watt-hour meters under the condition that the auxiliary devices are combined.