What is this standard about?
This part of IEC 60404 is applicable to grain oriented and non-oriented electrical sheet and strip for a.c. measurements of magnetic properties at frequencies up to 400 Hz and for d.c. magnetic measurements.
The object of this part is to define the general principles and the technical details of the measurement of the magnetic properties of electrical steel sheet and strip by means of an Epstein frame.
The Epstein frame is applicable to test specimens obtained from electrical steel sheets and strips of any grade. The a.c. magnetic characteristics are determined for sinusoidal induced voltages, for specified peak values of magnetic polarization and for a specified frequency.
The measurements are to be made at an ambient temperature of (23 ± 5) °C on test specimens which have first been demagnetized.
Measurements at higher frequencies are to be made in accordance with IEC 60404-10.
NOTE Throughout this standard the term "magnetic polarization" is used as defined in IEC 60050(221). In some standards of the IEC 60404 series, the term "magnetic flux density" was used.
