1.1 This practice covers procedures for conditioning electrical insulating materials (although not necessarily to equilibrium) prior to testing and the conditions under which they shall be tested. In general the physical and electrical properties of electrical insulating materials are influenced by temperature and relative humidity in a manner that materially affects test results. In order that reliable comparisons may be made of different materials and between different laboratories, it is necessary to standardize the humidity and temperature conditions to which specimens of these materials are subjected prior to and during testing.

1.2 This practice is similar to Practice D 618.

1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.