BS EN IEC 60404-18:2025

1   Scope The purpose of this part of IEC 60404 is to define 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 specifies methods to correct the influence of the self-demagnetizing
  field in the test specimen on the  demagnetization curve  obtained in an open magnetic circuit. The magnetic properties are determined from
  the corrected  demagnetization curve . 

    NOTE 1  These  SCM -methods can determine the magnetic properties of high-performance permanent magnet
     materials with coercivity higher than 2 MA/m. For the magnetic materials with coercivity
     higher than 1,6 MA/m, the methods of measurement in a closed magnetic circuit in accordance
     with [IEC 60404‑5](/search?q=IEC%C2%A060404%E2%80%915) can lead to significant mea...