Horizontal differential induction probe for defect analysis on pipes by stray flux technique has shape of parallelogram with angle in same direction as overrun angle of test head over defect

摘要

The induction probe has the shape of a parallelogram where the angle (5) of the parallelogram is in the same direction as the angle at which the test head passes over the defect. Individual probes (1-4) are arranged in the form of printed coils on a circuit board. Each circuit board has two parallel rows of printed probes with probes in one row offset relative to those in the other row.