The remote field eddy current (RFEC) technique is used to nondestructively evaluate ferromagnetic tubes. Evidently, this technique is especially attractive when the tubes must be inspected from the inside as well as original eddy current testing (ECT) is. Unlike the impedance plane analysis form of ECT, the technique is a through-transmission effect that reduces problems such as lift-off normally associated with ECT. In the inspection of steam generator tubes, the real issue is to detect the minute cracks grow up from the outside. However, using ECT, it is considered infeasible to find them accurately because of the limitations of penetration of eddy currents. This paper describes the results of numerical simulation for the RFEC technique applied to non-magnetic steam generator tubes. Two models are compared: axisymmetric and three-dimensional finite elements, and the A- PHI method is used to compute the RFEC signal.
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