Describes the standard method of measurement of lamp cap temperature rise which is to be used when testing tungsten filament or discharge lamps for compliance with the limits. Covers the method of test and the specifications for test lampholders for lamps fitted with various sizes of ES and BC caps. This method has been used widely for incandescent lamps but its application is not limited to that type of lamp. The contents of the corrigendum of March 1999 have been included in this copy.