Abstract: This gas flow measuring unit consists of a micro gas flow measuring probe, Which has a light orifice plate, and a flow linear intergrating instrument based on MCS8098. A design method of the probe is advanced. A subminiature differential pressure sensor is used in exactly detecting the differential pressure between the two sides of the orifice plate. The output current of the circuit is transferred distortionlessly to the integrating instrument, where the data is sampled and processed. This measuring unit is used in the ground test of a satellite propulsion system. It has great value in ensuring the reliability of propulsion systems while working in the outspace.

Key words: micr o-ga s-flow, or ifice plate, pr obe, mea sur ing unit