Loss measurements on amorphous materials using a field-compensated single-strip tester

Conventional methods of single-strip testing are not suitable for the range of high-permeability thin materials that have been developed for power devices during the past few years. The authors describe a field-compensated single-strip tester designed to measure the power loss and permeability of amorphous materials and other thin ribbons as well as more conventional electrical steels. Measurements on grain-oriented silicon iron confirm the accuracy of the system by comparison with standard test methods allowing for their nonabsolute nature. Measurements were successfully made on strips of as-cast and annealed amorphous material, and the errors associated with other techniques were illustrated. Increased loss was found when groups of specimens of amorphous material were tested together; some possible explanations for the effect are presented