4.1 Ovens used for thermal evaluation of insulating materials are to be capable of maintaining uniform conditions of temperature and air circulation over the extended periods of time that are required for conducting these tests. Specification D5423 specifies the permissible variations from absolute uniformity that have been accepted internationally for these ovens. These test methods include procedures for measuring these variations and other specified characteristics of the ovens.

1.1 These test methods cover procedures for evaluating the characteristics of forced-convection ventilated electrically-heated ovens, operating over all or part of the temperature range from 20 °C above the ambient temperature to 500 °C and used for thermal endurance evaluation of electrical insulating materials.

1.2 These test methods are based on IEC Publication 60216-4-1, and are technically identical to it. This compilation of test methods and an associated specification, D5423, have replaced Specification D2436.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.4 This 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.