Design and Experimental Validation of a Micro-Newton Torsional Thrust Balance for Ionic Liquid Electrospray Thruster

This work describes the advances on a micro-newton torsional thrust balance for ionic liquid electrospray thruster (ILET) being developed in National University of Defense Technology. The adopts an asymmetric pendulum arm about flexural pivot, and electrostatic comb device is used calibration, which makes compact allows measurement level with high accuracy. To minimize influence gravity results, two-dimensional adjustable counterweight mechanism adapted to entire make its mass center close pivot axis. Mechanical oscillations are passively damped eddy current damper. A series experimental studies carried out vacuum chamber; results provide validation that has good linearity range 2–30 μN, resolution better than 0.21 μN settling time step force less 7 s, can meet requirements ILET operating mode alternating voltage polarity. In addition, we find generated by power supply wire non-negligible needs be considered actual measurement.