Eddy current examination device without producing device and eddy current examination device

摘要

PROBLEM TO BE SOLVED: To ensure that a crack detection coil in an area close to an edge of an inspection object in eddy current flaw detection does not detect the edge and detects a crack instead.SOLUTION: An edge excitation coil 21 is disposed on the inside of an edge detection coil 20, and are planarly disposed a crack excitation coil 22 on the inside thereof, at a distance from a dead zone 3, and a crack detection coil 23 on the inside thereof. Currents in opposite directions are applied to the edge excitation coil 21 and the crack excitation coil 22 separated by the dead zone 3, so that no eddy currents are induced on the surface of an inspection object A and the dead zone 3 is formed. An edge A1 is detected by an edge detection coil 20 disposed on the outermost side, and a crack is detected by the crack detection coil 23 that is suppressed from detecting the edge A1 by the dead zone 3, so that the confusion of the edge A1 with the crack is eliminated, and it is possible to accurately detect a crack.SELECTED DRAWING: Figure 1