Precise Calibration of Propellant Flow and Forces in Specialized Electric Propulsion Test System

Precise readout values for propellant flow rates obtained from mass flow controllers are vital for the derivation of accurate and reliable figures that are indicative of thruster performance, such as the specific impulse and thruster efficiency. This is exceptionally important in thrusters employed for micropropulsion for orbit maintenance and drag compensation in small satellites, where a small uncertainty and deviation in propellant flow would lead to large errors in derived values. Therefore, it is crucial for researchers engaged in propulsion-based research to ensure that their gas flow controllers are calibrated and verified experimentally to be accurate before engaging in thorough experimental work. In this paper, an experimental method for the practical calibration of propellant feed systems in typical Hall thruster setups is tested. The results yield reliable calibration factors that have been applied for performance correction of miniature Hall thrusters. The corrected propellant flows correlate well with obtained ionization oscillation waveforms, indicating that the presented method for calibration is favorable and dependable for application to ground test facilities for thrust performance qualification.