METHOD AND DEVICE FOR DETERMINATION OF POSITION AND STATE OF OBJECTS INSIDE TUBE Russian patent published in 2003 - IPC

FIELD: pipe line systems. SUBSTANCE: proposed device includes receiving-amplifying channel, phase determination circuit and analysis circuit of received electromagnetic oscillations. Proposed method consists in radiating low- frequency electromagnetic oscillations inside or outside pipe line and receiving these oscillations on opposite side relative to pipe line wall; reference electric oscillations are generated in electromagnetic oscillation reception circuit and difference of phases between received and reference oscillations is determined and information and/or control signals are shaped depending on magnitude of said phase difference. Mode of operation of LC-circuit with reception of external electromagnetic oscillations is alternated with mode of operation of LC-circuit with radiation of natural electromagnetic oscillations; change-over of said modes is performed by breaking or restoring connection of output of LC-circuit capacitor. Proposed method enhances efficiency of locating objects inside pipe lines under conditions of considerable external parasitic electromagnetic action in zones where electric power lines are located and in proximity of industrial plants provided with high voltage converters, electromechanical units and/or system at high consumption of current at high noise-to-signal ratio. EFFECT: enhanced efficiency; extended functional capabilities. 9 cl, 2 dwg