Direct-reading iron-loss testing equipment for single sheets, single strips and test squares

The paper describes the two basic techniques by which a dynamometer wattmeter may be employed to measure specific iron loss, and shows how these methods have been applied to measurements on Lloyd-Fisher or Epstein samples and to the development of single-sheet testers and single-strip testers. All the equipments give direct readings of flux density, magnetizing force and specific iron loss. The advantages of single-sheet testing are emphasized particularly as a means for grading hot-rolled transformer steel.