Semiautomatic permeance tester for thick magnetic films

An apparatus has been developed for the measurement of the permeance (effective permeability-thickness product) of magnetic films for frequencies 1-100 MHz and permeances up to 20 000 μ with an accuracy of ±100 μ. This is suitable for permalloy films in the 0.5-5 μ thickness range, which are used in thin film recording heads operating in this frequency range.