Abstract
The standardized Epstein frame is a magnetic circuit for the normative measurements of magnetic properties of electrical sheet steel following the Wattmeter method. It was designed for convenient practical use in industry rather than as an accurate physical representation of magnetic power loss of the material. In principle, the Wattmeter method is based on the use of a homogeneous ring sample as the magnetic circuit. The double overlapping corners of the Epstein frame constitute a significant divergence from the topology of the homogeneous ring, and, thus, are the source of a substantial systematic error. This paper applies the simple method of summation of the reluctances of the complete magnetic circuit (CRS) for the determination of this error. The results for various types of electrical steel and for the frequency range of 40 Hz to 100 Hz are considered. Results of variations of the Epstein strip stacking scheme are also recorded.
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