Galois sequences in the non-destructive evaluation of metallic materials

A new eddy currents non-destructive evaluation technique for the investigation of deep defects is presented. The method joins the favourable features of the pulsed eddy currents approach with the peculiar properties of the Galois sequences to extend the detection area down to large depths. The proposed method has been successfully tested on a benchmark; the experimental results have been compared with the standard pulsed method and with numerical simulations. The comparisons confirmed the accuracy of the method and its effectiveness in allowing a significant improvement in deep defect detection.