Analysis of eddy current array probe signals according to arrangement of transmit-receive coil

Abstract

Eddy current array probe is consisted of several transmit coils and receive coils. The magnetic fields are generated by transmit coil and the eddy current is generated in the conducting materials by the time-varying magnetic field. Using the receive coil the magnetic field generated by source current of transmit coil and eddy current is caught. In this paper the eddy current signals of array probe according to arrangement of transmit coil and receive coil are analyzed. The type of defect is FBH and the depth of defects are 40[%], 60[%] and 100[%] of thickness of INCONEL 600 steam generator tubes in nuclear power plant. As the distance and bearings of transmit coil and receive coil are changed, the eddy current signals are obtained. To obtain these signals, three-dimensional electromagnetic analysis based on Maxwell's equation is performed using OPERA-3D. Analysis domain is discredited by tetrahedral mesh and the number of nodes is 1,014,467. The signal difference can be seen according to the arrangement of transmit-receive coil. The results in this paper can be helpful when the ECT signals from EC array probe are evaluated and analyzed. © 2009 The authors and IOS Press. All rights reserved.