METHOD OF INTRA-TUBE DEFECTOSCOPY OF PIPELINE WALLS Russian patent published in 2017 - IPC F17D5/06 G01R29/27 

FIELD: measuring equipment.

SUBSTANCE: method consists in measuring the frequency response of the electrical impedance of the near-surface layer of the pipe wall. Electrodes are axially moved inside the pipeline both continuously and discretely with an interval equal to the interelectrode distance. The defect areas are detected by determining the deviations of the frequency response of the electrical impedance from the given values with reference to the current coordinates of the section. According to the command formed in the control system, the electrodes are returned to the coordinates of the pipeline section with the defect detected, and a repeated defectoscopy is carried out, followed by processing the measurement results. Defects in the pipe wall are detected by the deviation of the frequency response of the electrical impedance of the near-surface layer of the pipe wall from the set values measured by the sounding signal in the frequency range specified depending on the depths of the wall probing and the interelectrode distance. The electrical impedance is measured by a non-contact capacitive coupling of electrodes arranged in circular rows with the inner surface of the pipeline.

EFFECT: increasing the accuracy and reliability of the defect detection.

5 cl, 3 dwg