Light sensor and image processing system as detectors of tracking deterioration

Two types of automatic sensing systems are proposed as detectors of tracking deterioration on the surfaces of organic insulating materials by means of the IEC (International Electrotechnical Commission) 587 test method. They are a light-pulse-count system (LPCS) with light sensors and an image processing system (IPS) with an MOS device camera. Experimental results obtained with the two methods are presented. It was confirmed that the LPCS gives an accurate correlation with the transition of tracking deterioration. On the other hand, it was shown that the IPS could easily measure the propagation speed of the carbon path and the carbonized area.<<ETX>>