The ability to test mass air flow meters under simulated temperature, humidity, and altitude conditions is crucial to successful product development. A closed loop test facility has been developed for this purpose and will be discussed in the paper. Environmental simulation capability, mass flow measuring technique, and various instrumentation methods are covered. The objective of the testing facility is for the research and developemnt of air flow meters for the transportation industry. Accuracy and control problems encountered in measuring mass air flow are discussed.
