“…In early days, a partial discharge signal was recognized by means of the features revealed on an elliptical trajectory. However, as a consequence of the long term technology progress made over the years, commercial instruments are now able to accurately sense partial discharge signals [14,15], emanating from an insulation facility, analyze the dielectric punchthrough process, provide a maintenance message and prevent catastrophes, but such commercial instruments, costing as much as a million dollars, preprocess field detected signals in their front end circuits, due to which part of intrinsic physical meanings contained in the signals are lost. For this sake, a diagnostic tool for pattern recognition of GIS defects is presented in this work.…”