Abstract: A method for detecting a hot spot at a connector (2) arranged on an electrical line, a heat-sensitive impedance module (4, 4a, 4b, 4c) being arranged at the connector (2), the electrical line and the heat-sensitive impedance module having an overall heat-sensitive impedance, the method comprising the following steps: determining a physical characteristic that is a function of said overall heat-sensitive impedance, and if said physical characteristic deviates from a predetermined reference value, emitting an alarm for detecting and locating a hot spot at said connector.

Abstract: A method uses at least: one line made up of at least two conductors insulated by a material whose insulation impedance depends locally on the temperature, the line running through the installation; a reflectometer periodically transmitting a reflectometry signal at one end of the line, the signal being propagated along the line, the reflectometer measuring the echoes received and comparing the amplitudes of the echoes with a given reference; a hot spot being detected when the amplitudes of a given number of successive echoes are greater than the given reference, the echoes being provoked by a local reduction of the value of the insulation impedance.

Abstract: A complete injection signal is provided having a digital spectrum formed from components weighted by a set of coefficients, in a preliminary step, the coefficients of the components included within a frequency band are attenuated resulting in an incomplete digital spectrum being obtained; in a next step, the analog signal composed from the incomplete digital spectrum is injected into the electrical line; in a next step, the echo corresponding to the injected signal is measured; in a next step, the digital spectrum of the echo is calculated; in a next step, the digital spectrum of the echo of the complete analog signal if the latter had been injected is estimated, the kth component of the estimated complete digital spectrum being equal to the kth component of the digital spectrum of the echo received multiplied by the ratio between the kth component of the digital spectrum of the complete injection signal over the kth component of the incomplete digital spectrum; in a next step, the measurement of the reflecto

Abstract: A method for automatically measuring physical characteristics of a cable, comprises at least the following steps: positioning on said cable of means for creating an artificial singularity; the injection, at a point of said cable, of an electrical test signal; acquisition of said signal reflected on the singularities that said cable includes so as to produce a first reflectogram; measurement, on said reflectogram, of the temporal position ?t of the peak of the signal derived from its reflection on said artificial singularity; determination of the propagation velocity vp=2x/?t of the signal in said cable from the temporal position ?t and from the position x of said means for creating an artificial singularity on the cable.

Abstract: A complete injection signal is provided having a digital spectrum formed from components weighted by a set of coefficients, in a preliminary step, the coefficients of the components included within a frequency band are attenuated resulting in an incomplete digital spectrum being obtained; in a next step, the analog signal composed from the incomplete digital spectrum is injected into the electrical line; in a next step, the echo corresponding to the injected signal is measured; in a next step, the digital spectrum of the echo is calculated; in a next step, the digital spectrum of the echo of the complete analog signal if the latter had been injected is estimated, the kth component of the estimated complete digital spectrum being equal to the kth component of the digital spectrum of the echo received multiplied by the ratio between the kth component of the digital spectrum of the complete injection signal over the kth component of the incomplete digital spectrum; in a next step, the measurement of the reflecto

Abstract: A method uses at least: one line made up of at least two conductors insulated by a material whose insulation impedance depends locally on the temperature, the line running through the installation; a reflectometer periodically transmitting a reflectometry signal at one end of the line, the signal being propagated along the line, the reflectometer measuring the echoes received and comparing the amplitudes of the echoes with a given reference; a hot spot being detected when the amplitudes of a given number of successive echoes are greater than the given reference, the echoes being provoked by a local reduction of the value of the insulation impedance.

Abstract: A method of testing a cable by distributed reflectometry, comprises: injecting into the cable a first periodic signal and a second periodic signal having the same number N of periods and the same number M of samples per period as the first signal; acquiring a measurement of the reflection, from impedance discontinuities of the cable, of each of said first and second signals; taking the average of said measurements of the reflection of at least one of said first or second signals over all of its periods to produce at least one reflectogram; determining the positions of faults in the cable on the basis of at least the reflectogram; the method being wherein each period of the second signal is injected into the cable with a delay or an advance which has an increasing predetermined absolute value for each successively injected period.

Abstract: A method for analyzing a cable, into which a first reference signal g is injected, calculates the dynamic correlation between a measurement f of the reflection, from at least one discontinuity in the cable, of the injected signal g and a second reference signal gp equal to the first reference signal g weighted by a frequency-dependent function modeling the propagation of a wave along the cable.

Abstract: A method of testing a cable by distributed reflectometry, comprises: injecting into the cable a first periodic signal and a second periodic signal having the same number N of periods and the same number M of samples per period as the first signal; acquiring a measurement of the reflection, from impedance discontinuities of the cable, of each of said first and second signals; taking the average of said measurements of the reflection of at least one of said first or second signals over all of its periods to produce at least one reflectogram; determining the positions of faults in the cable on the basis of at least the reflectogram; the method being wherein each period of the second signal is injected into the cable with a delay or an advance which has an increasing predetermined absolute value for each successively injected period.

Abstract: A method for automatically measuring physical characteristics of a cable, comprises at least the following steps: positioning on said cable of means for creating an artificial singularity; the injection, at a point of said cable, of an electrical test signal; acquisition of said signal reflected on the singularities that said cable includes so as to produce a first reflectogram; measurement, on said reflectogram, of the temporal position ?t of the peak of the signal derived from its reflection on said artificial singularity; determination of the propagation velocity vp=2x/?t of the signal in said cable from the temporal position ?t and from the position x of said means for creating an artificial singularity on the cable.