PROCEDURE DETECTING POINT OF LEAK IN PRESSURE PIPE-LINE AND FACILITY FOR ITS IMPLEMENTATION Russian patent published in 2003 - IPC

FIELD: instrumentation, establishment of coordinates of leak in underground pipe-lines of heat and water supply systems. SUBSTANCE: in correspondence with invention electromagnetic field is formed by plane-polarized wave in ground by way of electromagnetic sounding of ground along path of pipe-line. Signals with right-hand and left-hand circular polarization reflected from pipe-line are received. Signal with right- hand circular polarization gated by time proportional to depth of pipe-line lying. Signal with left-hand circular polarization is frequency-converted. Intermediate frequency voltage is isolated, it is multiplied with signal of right-hand circular polarization, harmonic voltage on stable frequency of heterodyne is isolated, it is limited by amplitude, phase shift between signals with right- hand and left-hand circular polarization is measured on stable frequency of heterodyne, measured value of phase shift is compared with reference value and results of comparison are used to make decision on presence of point of leak in tested pipe-line. EFFECT: raised measurement accuracy and resolution by depth thanks to exclusion of signal reflected from air-ground surface and correction of ambiguity of phase measurements. 2 cl, 1 dwg