Shielding of the Z-Component of the Magnetic Field in a 2-D Magnetizer With a Deep Yoke

Compact round rotational single sheet testers (RRSSTs) can achieve very high flux densities (~ 2 T at 60 H
_z
), owing to sinusoidal distribution of the magnetizing magnetomotive force (MMF), equalization of reluctance, a reduction in their diametrical size and longer stack lengths (deep yokes). The last two measures result in an increase in the magnetic field z-component (H
_z
), which is often reduced by shielding. This paper shows that a given shield distance is not effective in minimizing H
_z
over the entire flux density range. The impact of the magnetizer diametrical size and the yoke depth on H
_z
is also compared with shielding. Finally, this paper shows that magnetic properties contribute significantly to H
_z
at very high flux densities, whereas the magnetic interaction of the sample and shields, reduce the effectiveness of shielding in deep saturation at 2 T.