ASTM D 1934 : 2020

1.1This test method covers two procedures for subjecting electrical insulating liquids to oxidative aging:

1.2This test method is applicable to insulating liquids used as impregnating or pressure media in electrical power transmission cables if less than 10 % of the insulating liquid evaporates during the aging procedures. It applies and is generally useful primarily in the evaluation and quality control of unused insulating liquids, either inhibited or uninhibited.

1.3This test method is applicable to study the long-term behavior of an insulating liquid being considered for free breathing transformers. An unsealed vessel aging procedure, in presence of air or oxygen, allows greatly increased oxidation rate of the liquid. This procedure is rapid and provides a controlled thermal stress assessment.

1.4The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.5An open beaked test shall only be carried out on liquids with flash points at or above 130°C or 15°C above the oven temperature. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See 7.5 for a specific warning statement.

1.6This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.