This specification covers the performance requirements for four types (Types IA, IB, IIA, and IIB) of general-purpose air ovens of the gravity-convection and forced-ventilation types ordinarily used in testing operations. The temperature within the testing chamber shall be controllable by an automatic device and, when examined with appropriate test methods provided herein, shall be uniform within the tolerances for temperature uniformity, time constant, and rate of ventilation requirements for the particular type of oven.