This guide establishes uniform procedures for the testing of transmission line and station bus hardware in high voltage laboratories. Two tests are described. The fi rst one is a corona performance test. The second is a radio interference voltage (RIV) test. The fi rst test uses visible techniques to determine the onset of positive corona. The second test is a measurement of the RIV voltage according to ANSI C63.2 or CISPR 16-1-1 and CISPR 18-2: 2010. This guide does not address the permissible radio interference (RI) limits or specifi ed corona extinction voltages. They are set either by regulation or by agreement between the end user and hardware manufacturer. Purpose The purpose of this guide is to establish uniform procedures for the testing of transmission line and station bus hardware in high voltage laboratories. A uniform procedure is a prerequisite to assure such hardware is either free from visible corona or does not add any appreciable RI to that already being generated by the transmission line or substation conductors.