Commercial testing of sheet iron for hysteresis loss

The desirability of being able to determine quickly and with reasonable accuracy and cost the hysteresis and eddy losses in sheet iron for use in transformers and other alternating current apparatus is fully appreciated and need not be discussed. The arrangements that have been devised by various workers along this line, some of which have been described,∗ evince the fact that the subject has received much attention from time to time and that the methods of testing samples by means of ballistic galvanometer or by wattmeter test on complete apparatus are not entirely satisfactory.