[1A4] Towards tilt and lift-off invariant eddy current sensing for complex geometries
L Buck and R Hughes
University of Bristol, UK
Eddy current testing (ECT) is an established method for non-destructive testing of electrically conductive components. Sensitivity to small defects and material changes, speed of scanning and sample geometry flexibility can be enhanced through careful probe design and signal enhancement techniques. However, despite decades of research, ECT measurements remain susceptible to probe tilt and lift-off issues, especially in use on curved or complex samples. This paper documents a novel method for designing and operating tilt and lift-off invariant eddy current sensors to mitigate some tilt and lift-off problems. The method offers novel applications for ECT inspection of complex geometries. Finite element modelling is used to simulate suitable coil operating designs and experimental results are presented to evaluate the ability of prototype sensors to detect defects. The ability of the prototype sensors to eliminate tilt and lift-off issues shows practical promise for defect detection and in-line monitoring.
