Patent ID: 9158023
Filing Date: 2015-10-13
Classification: G01R,G01V

Abstract:
1. A method of evaluating at least one feature of a buried electrical cable that has a cable fault at a cable fault location, comprising the steps: a) positioning an evaluation apparatus at a first measuring position, wherein said evaluation apparatus includes at least one electromagnetic coil, an acoustic sensor and an output device; b) applying a first electrical pulse to said electrical cable, which produces a first magnetic field around said electrical cable and produces a first acoustic signal emitted from said cable fault; c) while said evaluation apparatus is positioned at said first measuring position, detecting said first magnetic field with said at least one electromagnetic coil to produce a first magnetic field information, and detecting said first acoustic signal with said acoustic sensor, and; d) from at least said first magnetic field information, determining a cable position information indicative of a cable position feature of said electrical cable relative to said evaluation apparatus; e) via said output device, outputting said cable position information to indicate said cable position feature of said electrical cable relative to said evaluation apparatus; f) determining a first time delay between said detecting of said first magnetic field and said detecting of said first acoustic signal; g) positioning said evaluation apparatus at a second measuring position different from said first measuring position; h) applying a second electrical pulse to said electrical cable, which produces a second magnetic field around said electrical cable and produces a second acoustic signal emitted from said cable fault; i) while said evaluation apparatus is positioned at said second measuring position, detecting said second magnetic field with said at least one electromagnetic coil to produce a second magnetic field information, and detecting said second acoustic signal with said acoustic sensor; j) determining a second time delay between said detecting of said second magnetic field and said detecting of said second acoustic signal; k) comparing said first time delay with said second time delay, and from a result of said comparing determining a fault position information indicative of a fault position feature of said cable fault relative to said evaluation apparatus; and l) via said output device, outputting said fault position information to indicate said fault position feature of said cable fault relative to said evaluation apparatus.