EXPERIMENTAL DESIGN OF PERMANENT MAGNET DEMAGNETIZATION CURVE USING APPROXIMATING EQUATIONS

Today the parameters and characteristics of permanent magnets are determined by means of computer as well as analogue‐to‐digital technics. Also digitizing oscilloscopes owing to the advanced digital processing of measured signals may contribute to the processing of measured data (averaging interpolation) and in mathematical operations. The measuring and calculation possibilities together with the possible rapid change of the magnetic state of a magnet due to the pulse magnetization makes the pulse test methods of magnets more and more frequent. The application of either single‐pulse or multiple‐pulse methods is possible. The idea of measurements when using both the latter methods is based on the assumption that the magnet before being subjected to tests is magnetized up to the saturation state. The single‐pulse method described briefly in and more comprehensively in, consists in recording and suitably processing the set of discrete values having a finite number of elements which appear during a single remagnetizing pulse of the magnet. The range of the recorded values covers flux densities from −Br to +Br i.e. covers one half of the hysteresis loop. In consequence, it is necessary to apply in this procedure a magnetic field k‐times exceeding the coercive force HcB of the tested magnet (depending on its type).