INTRA-PIPE FLAW DETECTOR (VERSIONS) AND METHOD OF USING SAID FLAW DETECTOR Russian patent published in 2010 - IPC G01N27/83 

FIELD: physics.

SUBSTANCE: housing of an intra-pipe flaw detector is fitted with magnetic field sensors and oscillatory circuits, each having a pair of inductance coils. The oscillatory circuit is connected to the input of a rectifier whose output is connected to the input of an integrator. When passing through the flaw detector, measurements are taken using the sensors and oscillatory circuits. The oscillatory circuits are periodically excited with a single electric pulse and damping characteristics in the circuits are measured. Presence of a defect is determined from the said damping characteristics. After passing through the flaw detector, data on presence of a defect from the oscillatory circuits are compared with data from magnetic field sensors. Defects on the inside and outside of the wall of the pipe are indicated by coincidence or non-coincidence of data on presence of defects respectively.

EFFECT: invention enables significant suppression of the effect of induced induction current generated through contact between components of the flaw detector and the inner surface of the inspected pipe during movement of the flaw detector.

122 cl, 9 dwg