This SAE Aerospace Recommended Practice (ARP) recommends performance requirements for test equipment used in dynamic testing of aviation oxygen breathing equipment. This document describes test equipment and methods used for testing continuous flow, demand and pressure demand regulators and their associated masks as well as filtered protective breathing devices; such articles of oxygen breathing or protective breathing equipment may be tested as individual components or as a complete system. This recommended practice covers but is not limited to the following types and classes of systems: Type I - mechanical breathing simulator (either bellows or piston type) only generating sinusoidal patterns; Type II - mechanical breathing simulator (generally cam-actuated, bellows or piston type or pre-programmed, servocontrolled) generating any shape of breathing pattern; and Type III - pneumatic breathing simulator pre-programmed, servocontrolled generating any shape of breathing pattern; Class A - military aircraft oxygen systems; and Class B - transport category and general aviation oxygen systems.