Output force characterization of the electromagnetic calibration device for low thrust measurement

In this article, experiments on a coil–magnet assembly were conducted to discuss the influences of the relative positions between a coil and a magnet on the electromagnetic calibration force. The experimental methods and steps were discussed. The input–output relationship of some coil-magnet assembly and the working ranges of the relative positions between the coil and the magnet were obtained. The error of the output electromagnetic force did not exceed 3% when the relative positions between the coil and the magnet were in the proposed working ranges. Based on the input–output relationship and the working ranges, the error of the electromagnetic force from the deviation error (3%) and the data fitting was obtained. The error of the data fitting can be ignored so that the electromagnetic force error of the coil–magnet assembly would not exceed 3%. When the error of the electromagnetic force was assessed accurately, the working ranges can be used to guide the design of the thrust pendulum, and the calibration error and the performance of the thrust pendulum can be evaluated accurately.