Theoretical and experimental results of the magnetic stray flux technique

Two versions of the automatic magnetic stray flux technique are employed for non-destructive testing of steel products. In one version, the stray flux signal of rotationally symmetric, cylindrical components are recorded by orbiting stray flux probes and electronically evaluated for defect localisation. In the second version (magnetography), the stray flux of defects is stored on a magnetographic tape unwinding on the test piece, which is scanned by a magnetic microprobe orbiting at high speed. (orig./RW)