This recommended practice presents a number of tests for use in determining the significant parameters and performance characteristics of electronics transformers and inductors. These tests are designed primarily for transformers and inductors used in all types of electronics applications, but they may apply to the other types of transformers of large apparent-power rating used in the electric power utility industry. Some of the tests described are intended for qualifying a product for a specific application, while others are test practices used widely for manufacturing and customer acceptance testing. Clause 4 is intended to serve as a guide for particular application categories. The tests described in this recommended practice include those most commonly used in the electronics transformer industry: electric strength, resistance, power loss, inductance, impedance, balance, ratio of transformation, and many others used less frequently. Revision Standard - Superseded. A number of tests are presented for use in determining the significant parameters and performance characteristics of electronics transformers and inductors. These tests are designed primarily for transformers and inductors used in all types of electronics applications, but they may apply to the other types of transformers of large apparent-power rating used in the electric power utility industry.