This section of IEC 60404 pertains to both grain-oriented and non-oriented electrical sheets and strips for alternating current (a.c.) measurements of magnetic properties at frequencies up to 400 Hz, as well as for direct current (d.c.) magnetic measurements.
The purpose of this section is to outline the general principles and technical specifics for measuring the magnetic properties of electrical steel sheets and strips using an Epstein frame. The Epstein frame can be used for test samples derived from electrical steel sheets and strips of any grade. The a.c. magnetic characteristics are assessed for sinusoidal induced voltages, specified peak values of magnetic polarization, and a designated frequency.
Measurements should be conducted at an ambient temperature of (23 ± 5) °C on test specimens that have been demagnetized prior to testing. For measurements at higher frequencies, the procedures outlined in IEC 60404-10 should be followed.
NOTE: In this standard, the term “magnetic polarization” is defined as per IEC 60050(221). Some standards in the IEC 60404 series previously used the term “magnetic flux density.”
