Low permeability reference standards with improved high magnetic field strength performance

Summary form only given, as follows. Commercial instruments for determining the relative magnetic permeability of weakly magnetic materials require traceable calibration. This is achieved using reference standards of known permeability. These materials suffer to some extent from the fact that their relative magnetic permeability varies with the applied magnetic field strength. When used to calibrate instruments, this can introduce significant errors. We will report the development of a material which improves this situation. By uniformly dispersing iron particles in an acrylic matrix their self demagnetized properties are substantially retained and consequently the permeability changes with applied field are significantly smaller than for conventional materials.