AN A.C. FIELD MEASUREMENT SYSTEM FOR DETECTING AND SIZING DEFECTS IN A CONDUCTOR

摘要

An a.c. field measurement testing system comprises a probe including a yoke (10) for inducing a uniform a.c. field, sensor means (7, 8. 9) comprising a first coil (8) having a longitudinal axis extending in a first direction and a second coil (9) having a longitudinal iris extending in a second direction orthogonal to the first direction and means (11) for effecting energisation of the field, the arrangement being such that signals produced by the coils (8, 9) indicative of defects in a test piece are processed whereby one component of a magnetic field is plotted against another in a display.