Advances in Signal Processing to Reduce Lift-off Noise in Eddy Current Tests

Nowadays, Non Destructive Testing and Evaluation (NDT/NDE) are frequently used to evaluate integrity of manufactured articles in civil or industrial applications. In this framework, Eddy Current Test (ECT) technique has a primary role for inspection of conducting materials. Solution of many related inverse problems requires an accurate comprehension of mea- sured data: it is one of the most challenging problem in this context. That's why a suitable signal pre-processing is necessary. In this paper, advanced signal processing techniques are evaluated in order to reduce the impact of lift-off effect on the eddy current data. Some hybrid approaches are also depicted, with encouraging results.