Strain gauge based thrust measurement system for a stationary plasma thruster

A thrust measurement system has been developed for the purpose of measuring the thrust produced by a stationary plasma thruster. The measurement system designed and fabricated mainly consists of a thrust balance assembly with strain gauge sensors and associated signal conditioning circuitry. Performance of the system developed was studied, in a vacuum chamber under space simulated conditions, by activating the thruster using xenon as the propellant. Details of the in situ calibration procedure followed are given. The thrust output for discharge powers ranging from 170 to 260 watts was measured and found to be in the range of 4-14 millinewtons. The measurement accuracy and resolution were found to be ±1 mN and 0.3 mN respectively. Specific impulse and thrust efficiency were also estimated.