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A Rotating Field Automated Measurement System for the Characterization of Ferromagnetic Materials

Ramos, H. ; Girão, P.M.

Journal of Appl. Physics Vol. 69, Nº 8, pp. 5103 - 5105, April, 1991.

ISSN (print): 0021-8979
ISSN (online): 0021-8979

Journal Impact Factor: 2,201 (in 2008)

Digital Object Identifier: 10.1063/1.348137

This paper presents an automated measurement system which uses general purpose IEEE‐488 controlled devices for the characterization, according to a Preisach‐type model, of ferromagnetic materials subjected to magnetic fields of variable amplitude and direction. For that purpose, the measurement of component values in two orthogonal directions of both magnetic field and magnetic induction are required. The magnetic induction in the sample is obtained by using analog integration of the resulting induced electromotive forces in two test coils when the magnetizing current is changed. The magnetic field inside the sample is obtained by measuring the electromotive forces induced in two air core sensing coils placed on both surfaces of the sample. Besides hardware and software details, this paper presents results of tests conducted on ferromagnetic materials commonly used in electrical apparatus.