This standard specifies the terminology, product classification, technical requirements, test methods and inspection rules for electric meters. This standard applies to mechanical positive counters used in installed electricity meters, including single-rate counters (including forward and reverse cumulative counters, forward and reverse double-row counters), and dual-rate counters. and three-rate meters. This standard does not apply to maximum demand watt-hour meters, prepaid watt-hour meters, standard watt-hour meters, separate meters for remote sensing watt-hour meters and meters with special requirements.