IEC 60404-5 Ed. 2.0 b:1993, Magnetic materials - Part 5: Permanent magnet (magnetically hard) materials - Methods of measurement of magnetic properties

Applies to magnetically hard materials only. The described method makes use of a closed loop simulating a ring. Two alternative methods are given for intrinsic coercivity up to and including 600 kA/m and one for materials with higher intrinsic coercivity (e.g. rare earth cobalt alloys).