1 Scope
This Technical Report describes the general principle and technical details of the
methods of measurement of the DC magnetic properties of permanent magnet materials
in an open magnetic circuit using a superconducting magnet (SCM).
This method is applicable to permanent magnet materials, such as those specified in
IEC 60404‑8‑1, the properties of which are presumed homogeneous throughout their volume.
There are two methods:
– the SCM-Vibrating Sample Magnetometer (VSM) method;
– the SCM-Extraction method.
This document also describes methods to correct the influence of the self-demagnetizing
field in the test specimen on the demagnetization curve measured in an open magnetic circuit. The magnetic properties are determined from
the corrected demagnetization curve .
NOTE These SCM-methods can determine the magnetic properties of permanent magnet materials
with coercivity higher than 2 MA/m. The methods of measurement in a closed magnetic
circuit specified in IEC 60404‑5 can lead to significant measurement error due to saturation effects in the pole pieces
of yoke for the magnetic materials with coercivity higher than 1,6 MA/m (see IEC 60404‑5).