IEC TR 61807:1999

Foreword
1 Scope
2 Reference documents
3 Definitions
4 Symbols
5 Review of existing permanent magnet materials
6 Measuring equipment
7 Evaluation of measured data
8 Test report
Annex A - Results of an inter-comparison of measurement
          on magnetically hard (permanent magnet)
          material at elevated temperature
      A.1 - Introduction
      A.2 - Test specimens
      A.3 - Method of measurement
      A.4 - Results
      A.5 - Conclusions
Annex B - Example calculations
      B.1 - Magnetically anisotropic sintered NdFeB
            magnet
      B.2 - Magnetically anisotropic sintered
            Sr-ferrite magnet

Provides methods for measuring magnetically hard materials, at elevated temperatures. Magnetically hard materials (permanent magnet materials) are classified in IEC 60404-1 and their properties are specified in IEC 60404-8-1. The methods of measurement of the magnetic properties of magnetically hard materials at room temperature have been specified in IEC 60404-5 for closed magnetic circuits and in IEC 60404-7 for open magnetic circuits, respectively. The applications of magnetically hard materials are now expanding to elevated temperatures and it is therefore required to specify and guarantee the magnetic properties of these materials over their working temperature range. In IEC 60404-8-1 temperature coefficients of remanence (or saturation) and J-coercivity have been specified in addition to basic properties such as maximum magnetic energy product ((BH)max), remanence (Br), B-coercivity (HcB), J-coercivity (HcJ), recoil permeability (µrec) and density.