Abstract
In this paper, the performance of two probes of split TR structure is evaluated by numerical analysis aiming at the enhancement of sizing capability of ECT for a deep crack. The structures of the two probes are respectively of reflection and transmission type consisting of a rectangular excitation unit and a pancake pickup coil. A modified way is proposed for the reflection type probe to improve the eddy current penetration. Numerical results reveal that the modified reflection type probe and the transmission type probe are promising for the sizing of deep cracks.