Simulation and test for the micro-newton electromagnetic calibration force measurement

For micro-Newton (mu N) level thrust measurement, achieving highly accurate calibration forces is crucial as an initial step. To provide high-precision and wide-range electromagnetic calibration forces, this study introduces a C-type magnetic circuit structure and a rectangular coil combination method. The magnetic field distribution within the device's characteristic region was examined using the finite element method, and the impact of the relative positions of the rectangular coil and magnet was explored. Subsequently, calibration experiments were conducted on a specially developed platform. The primary findings are as follows: The electromagnetic force calibration range is from 0.097 to 237.32 mu N, with the maximum error between experimental measurement data and simulation results being 1.73%. With a coil current resolution of 10 mu A, the measured resolution of the calibration force exceeds 0.1 mu N. Within the characteristic region, the magnetic field distribution exhibits high uniformity, with a maximum deviation rate of only 0.7%. This research establishes a technique for micro-Newton level thrust measurement.