METHOD FOR DETECTING DEFECTS IN PIPELINES Russian patent published in 2012 - IPC G01N29/04 

FIELD: machine building.

SUBSTANCE: acoustic transducers are installed; acoustic vibrations are recorded; location of defect on the inspected section of pipeline is determined and recorded; at that, acoustic vibrations are recorded on mode of radial vibrations of circular hollow cylinders on transverse piezoelectric effect in frequency band of 1-25 kHz range. At that, current-collecting electrodes are applied on side surfaces of hollow cylinder; diagnostic module is arranged inside pipeline and equipped with acoustic transducers by means of which there determined are non-linear properties of the controlled medium by determining the function relating the medium reaction pressure to excitation pressure; at that, emitting and receiving transducers are installed at distances l/l_σ=1 from each other; acoustic signals are emitted at frequencies of 140 and 150 kHz; standard histograms of probability density are determined for each signal; by polynomial approximation there determined is analytical expression for each histogram; non-linearity function and values of moment functions are calculated, which characterise the change of the shape of normal distribution law; foreign inclusions are determined in the controlled medium as per the change of the shape of distribution law.

EFFECT: improving reliability of defect detection in pipelines.

2 dwg