Abstract :
GRAPHICAL RECORDING of hysteresis loops or magnetization curves by means of a hysteresigraph is in many instances a much more convenient way of obtaining desired magnetic data than is the usual ballistic method. Unsymmetrical hysteresis loops, for example, may require considerable laborious procedure if obtained in the usual manner, but are easily recorded by some types of hysteresigraphs. The photoelectric hysteresigraph described herein is an instrument which readily records initial magnetization curves or any desired symmetrical or unsymmetrical hysteresis loops.