Detection of axial and circumferential notches using transceiver rotating field probe for tube inspection

The detection ability of a rotating field transceiver probe designed for axial and circumferential notches for inspecting tubes is studied in this paper. The transceiver probe consists of three identical windings, located 120° apart, on the same physical axis. A three-phase sinusoidal current sourc e is used for exciting the coils. The probe achieves the functionality of a mechanical rotating probe electronically and eliminates the need for mechanical rotation. A three-dimensional finite element model is used to simulate and predict the response of the probe to a variety of machined notches. The feasibility of detecting the axial and circumferential position of a defect by analyzing the amplitude and phase of the transceiver probe signals is studied. A prototype of the probe was built and evaluated using an Inconel tube with axial and circumferential defects.