A magnetic test apparatus, in accordance with one embodiment, comprising a rotor coupled to a drive shaft, wherein the drive shaft is mechanically coupled to a drive system; a stator coupled to at least one brush holder; at least one brush held by the brush holder, wherein the brush is held in contact with the rotor; a housing for supporting the rotor and the stator; and a magnet for providing a magnetic field in the vicinity of the at least one brush.