Patent ID: 8810254

Claim:
An apparatus for locating a fault at a fault location in an electrical cable, wherein at least the fault location of the cable is covered by a cover medium, and wherein said apparatus comprises: an electrical voltage pulse generator adapted to feed into the cable a sequence of voltage pulses that respectively cause voltage discharges, arc-overs, breakdowns, breakthroughs and/or sparking arcs at the fault, which cause emission from the fault of a sequence of acoustic emitted signals and a sequence of electromagnetic emitted signals respectively associated with the acoustic emitted signals and wherein the acoustic emitted signals and the electromagnetic emitted signals respectively propagate through the cover medium from the fault location to one or more detection locations; a portable receiver that is portably movable to be selectively located at any selected one of the detection locations, and that comprises an electromagnetic sensor adapted to detect at said selected detection location electromagnetic received signals including said electromagnetic emitted signals, and an acoustic sensor adapted to detect at said selected detection location plural successive acoustic received signals including said acoustic emitted signals and acoustic interference noises superimposed on said acoustic emitted signals; and an interference suppression arrangement that is connected for signal transmission with said portable receiver, and that is adapted to reduce or eliminate the interference noises from the acoustic received signals, and that comprises: a memory that is connected for signal transmission with said acoustic sensor, and that is adapted to store the plural successive acoustic received signals, a processing unit that is connected for signal transmission with said memory, and that stores and is adapted to execute a signal processing algorithm by which a respective one of the acoustic received signals is subjected to a signal processing with reference to or in combination with a preceding one of the plural successive acoustic received signals stored in said memory, wherein said signal processing eliminates, reduces or suppresses said acoustic interference noises included in said acoustic received signals, a timing unit that is connected for signal transmission with said electromagnetic sensor, and that is connected for signal transmission with at least one of said memory and said processing unit, and that is adapted to synchronize the signal processing with start time points of the acoustic received signals by reference to detected start time points of respective ones of the electromagnetic received signals respectively associated with respective ones of the acoustic received signals, and an evaluation unit that is connected to an output of said processing unit, and that is adapted for evaluating or outputting an output result of the signal processing according to said signal processing algorithm by said processing unit.