Electricity meters used for tariff or certification purposes must comply with the technical standards stipulated by the Measurement Law. These technical standards provide some 30-plus tests, including the electrical performance test, insulation performance test, mechanical performance test and weatherproof test.

It is practically impossible to conduct all these tests for every mass- produced electricity meter due to the huge cost and time involved. Therefore, these tests are conducted on samples of newly developed electricity meters and those passing the tests are given a type approval number. Those electricity meters which are an identical type to an approved sample are regarded as complying with the technical standards and their verification process omits the said tests. The type approval of electricity meters in Japan is carried out by the JEMIC. Since the type approval system was first introduced in 1911, more than 3,000 types of electricity meters have received the type approval.

Type Approval Flow Chart

Next figure shows the type approval flow chart.