Abstract: A stator testing device for a dynamoelectric machine formed from a plurality of laminations defining a plurality of substantially parallel stator teeth each extending over a preselected length of the stator. The stator testing device includes a housing having a bottom face adapted to be disposed adjacent the stator teeth and a face cover extending outwardly from said bottom face. A chattock coil for detecting stator axial currents is disposed within said housing. The chattock coil has a pair of end portions with bottom surfaces each extending to the bottom face of said housing. A pair of brackets are removably attached to the face cover of said housing, and a magnet is removably attached to each bracket. The magnets are located on the brackets so that the bottom surfaces of the pair of magnets are positioned adjacent to selected corners of adjacent stator teeth and remain in positional relationship to the selected corners as the housing is moved over a preselected length of said stator.

Abstract: An electrical generator inspection system comprises an electro-magnetic core imperfection detector that provides an analog signal representative of fault currents detected between adjacent laminations of a stator core; an analog-to-digital converter coupled to the detector for converting the analog signal to a digital signal; a digital filter coupled to the output of the converter for digitally filtering the digital signal to remove noise therefrom; and means for storing predetermined signal criteria and for comparing the filtered digital signal to the predetermined criteria to determine the location of the insulation defects along the stator core. In one embodiment, the system further comprises means for storing the filtered digital signal in a memory.