Covers the minimum requirements for ventilated and heated multi-chamber ovens used for thermal endurance evaluation of electrical insulation and of any other appropriate thermal conditioning application where the use of single-chamber ovens is inappropriate.Covers ovens designated to operate over all or part of the temperature range from 20 K above ambient to 500°C.Gives acceptance tests and in-service monitoring tests for both unloaded and loaded multi-chamber ovens and conditions of use.