Quantitative Determination of Magnetic Properties by Use of Cathode-Ray Oscilloscope

This paper describes a means of producing the core loss loops of samples of magnetic strips on an oscilloscope screen and a method of obtaining the heat loss from the areas of these loops. The standard Epstein test for obtaining the core loss requires a correction for corner effects due to stacking of the laminations, whereas the method described here circumvents this problem by utilizing only the center portion of a relatively few short strips of the test material. Since quantitative measurements are made, circuit refinements, such as negligible phase shift couplings between amplifier stages and stabilized voltage supplies, are incorporated into the circuits.