INTRAPIPE FLAW DETECTOR Russian patent published in 2001 - IPC

FIELD: inspection of space of main oil and gas product lines. SUBSTANCE: belt of sensitive levers pressed against internal surface of pipe-line is fixed on body of flaw detector. Body houses means processing and storing measured data, odometer system and electromagnetic marking transmitter determining position of flaw detector inside pipe-line. Deviations of levers are measured by transmitters of angle of turn based on Hall elements with simultaneous measurement of temperature. Two elastic collars fitting snugly to surface of pipe-line are placed in front of belt of sensitive levers. Area between first and second collars communicates with area downstream of second collar through holes in collar and/or body. Test of temperature of Hall elements enables corrections to be introduced into given measurements. Structural implementation of collars provides for smoothing of abrupt changes of temperature and of temperature gradient of Hall elements. EFFECT: improved functional reliability of flaw detector. 9 cl, 4 dwg