METHOD FOR MEASURING AND SEARCHING FAULT POINT OF CABLE

摘要

PURPOSE:To eliminate the need for calculation and judgment without requiring skilled techniques by detecting that the amplitude difference of the 1st and 2nd voltages attains approximately zero thereby measuring and searching a fault point. CONSTITUTION:An oscillator 61 is oscillated at the lowest possible frequency in order to minimize the influence of the electrostatic capacity between the cores of a cable. The AC signal from the oscillator 61 and the AC signal subjected to frequency multiplication by a frequency multiplier 6 are transmitted to a faulty cable core 63 having defective insulation. On the other hand, a leakage flux is detected by a pickup coil 65 from the outside of the sheat of the faulty cable 64 along said cable on the reception side. The detected two AC signals are subjected to the removal of noise components by a band pass filter 66 and are then calculated and outputted. The need for the calculation and judgment is thus eliminated without requiring the skilled techniques.