| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a remote field eddy current flaw detection system and a remote field eddy current flaw detection method capable of improving defect detection performance by reducing noise in a bent pipe. <P>SOLUTION: A detection coil 203 is a two-layer structure in which an outer coil 301 of a large diameter and an inner coil 302 of a small diameter are on a concentric axis and is a structure in which coils 303 and 304 in the same structures are arranged in an axial direction in two lines. The two outer coils 301 and 303 are differentially connected to each other, and the two inner coils 302 and 304 are differentially connected in the same manner. In the case of having no defect, an X2-Y2 signal converted by a matrix A is the same as an X1-Y1 signal (step 1), and is zero when subjected to differential arithmetic (step 2). On the other hand, in the case of having a defect, the X2-Y2 signal converted by the matrix A is not the same as the X1-Y1 signal (step 1), but an X3-Y3 signal is outputted when subjected to differential arithmetic (step 2). Further, an X-Y signal representing the size of the defect is outputted by a matrix B. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
