Computations of the accuracy of VSM

The accuracy of the measurements by vibrating-sample magnetometer (VSM) has been studied by the computations of the sensitivity function. The arrangement of the coils is important to approach a wide spatial-uniformity of the sensitivity function. The errors due to the directional displacements of the sphere are lower than 2% if the mis-alignments are controlled to within some specific values. The uncertain radius of the sphere is also an origin of errors.