Structure and working principle: induction type (mechanical type), static type (electronic type), mechanical and electrical integrated (hybrid type) according to the access power supply properties: AC table, DC table according to the accuracy level: common common table: 0.2s, 0.2s, 0.2, 0.5, 1.0, 2.0 and other standard table: 0.01, 0.05, 0.2, 0.5, etc. According to the installation connection mode: Direct access type, indirect access type according to electrical equipment: single-phase, three-phase three-wire, three-phase four-wire electricity meter.