| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a remote field eddy current flow detection technology which improves detection sensitivity of an indirect magnetic field while eliminating an influence of a direct magnetic field from an exciting coil and is excellent in the detection accuracy of defects. <P>SOLUTION: The remote field eddy current flow detector 10 includes: the exciting coil 31 which gives the direct magnetic field to an object 30 to be inspected to induce eddy current; and a detection coil 32 which detects the indirect magnetic field to be induced from the eddy current. The detection coil 32 is arranged so that its center axis Q becomes approximately perpendicular to a surface S of the object to be inspected, and when an interval between the exciting coil 31 and the detection coil 32 is W, distance from the surface S of the object to be inspected to the remotest point of the exciting coil 31 is H, and thickness of the object to be inspected is H, a relational expression of W≤(H+2T)×2 is satisfied. <P>COPYRIGHT: (C)2012,JPO&INPIT |
