1.1 This test method covers the accelerated life testing of electrical grade magnesium oxide (MgO) under conditions involving thermal cycling to an elevated temperature. The test determines both the rate at which electrical insulation impedance (Note 1) or test current through the insulation changes with time and the time span resulting in complete failure of a test cell incorporating the sample under test.

Note 1-At test temperatures, capacitive and inductive reactance are negligible, and therefore impedance values are considered essentially resistive.

1.2 This standard does not purport to address all of the safety problems 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. For specific safety precaution, see 9.4.1.

1.3 The values stated in acceptable metric units are to be regarded as the standard.