In this paper, the distribution of the magnetic field in a 300 mm RSST
(rotational single sheet tester) is determined. Measurements have bee
n carried out on GO and NO samples, using Hall probes, for three excit
ation axes: rolling, transverse and 45 degrees. The influence of the m
aterial anisotropy and the yoke-sample air gap is reported. Variation
of the field perpendicular to the sample plane justifies using the dou
ble H-coil method.