METHOD AND DEVICE FOR DETECTING LEAKAGE SITE IN PRESSURE PIPELINE Russian patent published in 2007 - IPC G01M3/08 F17D5/06 

FIELD: measuring technique.

SUBSTANCE: method comprises electromagnetic probing the soil along the trajectory of the pipeline and receiving signals with right and left circular polarization reflected from the pipeline. The right polarization signal is strobed by time proportional to the depth of the pipeline. The left polarization signal is converted in frequency, and the voltage of intermediate frequency is extracted. The harmonic voltage is extracted at a stable frequency. The signal is limited in amplitude. The phase shift is measured between the signal with right and left polarization at the stable frequency, and constant voltage proportional to the measured phase shift is shifted in phase by 90°. The initial and shifted constant voltage are multiplied twice. The initial and shifted voltage of the second extent are multiplied with the use of a scaling coefficient K_M=6. The product is subtracted from the initial constant voltage of fourth extent and the results are summarized with the shifted constant voltage of fourth extent. The voltage obtained is compared with the reference voltage, and the presence of leakage site in the pipeline to be tested is judged by the difference obtained.

EFFECT: enhanced reliability.

2 cl, 2 dwg