This article presents the theory and operation of a null-type, inverted pendulum thrust stand. The thrust stand design supports thrusters having a total mass up to 250 kg and measures thrust over a range of 1 mN to 5 N. The design uses a conventional inverted pendulum to increase sensitivity, coupled with a null-type feature to eliminate thrust alignment error due to deflection of thrust. The thrust stand position serves as the input to the null-circuit feedback control system and the output is the current to an electromagnetic actuator. Mechanical oscillations are actively damped with an electromagnetic damper. A closed-loop inclination system levels the stand while an active cooling system minimizes thermal effects. The thrust stand incorporates an in situ calibration rig. The thrust of a 3.4 kW Hall thruster is measured for thrust levels up to 230 mN. The uncertainty of the thrust measurements in this experiment is +/-0.6%, determined by examination of the hysteresis, drift of the zero offset and calibration slope variation.
[1]
J. R. Pierce,et al.
Scientific foundations of vacuum technique
,
1949
.
[2]
T. W. Haag.
Thrust stand for high‐power electric propulsion devices
,
1991
.
[3]
Thomas W. Haag.
Thrust stand for pulsed plasma thrusters
,
1997
.
[4]
Staffan Persson,et al.
SMART-1 mission description and development status
,
2002
.
[5]
Kurt A. Polzin,et al.
Thrust stand for electric propulsion performance evaluation
,
2004
.
[6]
John R. Brophy,et al.
Deep Space 1 Flight Spare Ion Thruster 30,000-Hour Life Test
,
2009
.