MAGNETIC MOMENT OF PERMANENT MAGNET MEASUREMENT WITH NONLINEAR LEAST SQUARES FITTING METHOD

Michał Nowicki – Dorota Jackiewicz – Roman Szewczyk

   In the paper, a procedure for magnetic moment measurement, utilizing single sensitive magnetometer and linear table is de-scribed. The object under test, for example a permanent magnet, is positioned with its main axis along the sensitive axis of the magnetometer's moving probe, and the magnetic field strength is recorded, as well as the probe precise position. The results of measurement are then processed in the Matlab software, and the non-linear least squares curve fitting is done using the Leven-berg-Marquardt algorithm. The fitting is performed for the magnetic dipole magnetic field strength versus distance model. Thus it is possible to measure both the object's magnetic moment and distance from the magnetometer.

Keywords: magnetic moment, magnetoresistive sensor, Levenberg-Marquardt algorithm

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