The cables take up a large proportion in power supply line. The cables used in industry and the business sector in operation for some time will appear aging and hidden trouble for accident. It may cause significant economic losses if not taking timely measures. The cable insulation condition is usually can be divided into good, not good, bad and the failure. Assessing the cable status on the basis of the daily maintenance data, test data and on-line monitoring data has a momentous engineering value a...