1.1 This test method determines the resistance of mineral transformer oils to oxidation under prescribed accelerated aging conditions. Oxidation stability is measured by the propensity of oils to form sludge and acid products during oxidation. This test method is applicable to new oils, both uninhibited and inhibited, but is not well defined for used or reclaimed oils. Note 1A shorter duration oxidation test for evaluation of inhibited oils is available in Test Method D 2112. Note 2For those interested in the measurement of volatile acidity, reference is made to the work of IEC Subcommittee 10A. 1.2 The values stated in metric units are to be regarded as the standard. 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.