This part of IEC 60243 gives methods of test for the determination of the short-time electric strength of solid insulating materials at power frequencies@ that is@ those between 48 Hz and 62 Hz. It does not consider the testing of liquids and gases@ although these are specified and used as impregnants or surrounding media for the solid insulating materials being tested. NOTE ?C Methods for the determination of breakdown voltages along the surfaces of solid insulating materials are included.