The purpose of this test method is to verify the electrical strength of components and insulating materials in electronic equipment by partial discharge measurement. The test method covers the detection of partial discharge by electrical means in components and insulating materials. Test conditions, terminology, test apparatus, calibration and test requirements are included in this method. The test method is based on IEC 270 with respect to terminology, testing principle and calibration procedure. For cases where, additionally, the values of partial discharge inception and extinction voltage are of interest, a measuring procedure is described in IEC 664-1, annex D.