A voice coil based electromagnetic system for calibration of a sub-micronewton torsional thrust stand

This paper presents the development of an alternative electromagnetic calibration system. Utilising commercially available voice coils and permanent magnets, the proposed system is able to generate linear, repeatable, and consistent steady-state calibration forces at over four orders of magnitude (30–23,000 µN). It is also capable of producing calibration impulse bits in the range of 12–668 µNs. The maximum uncertainty errors of the calibrator are evaluated as 18.48% and 11.38% for steady-state and impulsive forces calibration, respectively. Its performance is compared to other existing electromagnetic calibration techniques. Capability of the system is then demonstrated in calibrating a sub-micronewton torsional thrust stand.