PD IEC TR 63304-2021 Permanent magnet (magnetically hard) materials — Methods of measurement of magnetic properties in an open magnetic circuit using a superconducting magnet.
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).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60404-5, Magnetic materials – Part 5: Permanent magnet (magnetically hard) materials – Methods of measurement of magnetic properties
IEC 60404-8-1 , Magnetic materials – Part 8-1: Specifications for individual materials – Magnetically hard materials
IEC 60050-1 21 , International Electrotechnical Vocabulary – Part 121: Electromagnetism
IEC 60050-1 51 , International Electrotechnical Vocabulary – Part 151: Electrical and magnetic devices
IEC 60050-221 , International Electrotechnical Vocabulary – Chapter 221: Magnetic materials and components
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-1 21 ,IEC 60050-1 51 , IEC 60050-221 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 demagnetization curve
part of a hysteresis loop in which the magnetic polarization goes from the remanent magnetic polarization to zero when the applied magnetic field strength varies monotonically, as illustrated in Figure 1.PD IEC TR 63304 pdf download.