METHOD OF DETERMINING POSITION AND TYPICAL SIZE OF LEAKAGE IN UNDERGROUND PIPELINE Russian patent published in 2009 - IPC F17D5/02 

FIELD: physics.

SUBSTANCE: electromagnetic radiation is generated in a pipeline using a radiator placed in the pipeline. Ultrahigh frequency electromagnetic radiation with time-varying frequency is transmitted along the pipeline. Electromagnetic radiation leaking out from the leaking hole is received using two panoramic receivers, the tuning frequency range of which coincides with the radiation band of the emitter. The antennae have a circular and cardioid pattern. The cardioid pattern is rotated until superposition of zero collapse with direction of incoming electromagnetic radiation and the moment of said superposition is recorded. Position of the leaking hole is determined from the minimum of the cardioid pattern of the antenna, and the typical size of the hole is determined from the frequency mark on the screen of an observation oscilloscope. Voltage of intermediate frequency of each panoramic receiver is detected on frequency and amplitude, and the voltage obtained after frequency detection is differentiated with respect to time, selected according to polarity, compared according to polarity with voltage obtained after amplitude detection, and from the comparison results, a decision can be made on further processing of the received signals.

EFFECT: increased noise immunity, accuracy and disambiguation of measurements of critical frequency for of signals, generated by the leaking hole in an underground pipeline, by suppressing false signals received over an image channel at frequency f_i.

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