An improvement in defect detection through integration of Rotating Eddy Currents and multi-tone excitation

In this paper, a novel improvement of the Rotating Eddy Current (REC) technique is proposed, integrating multi-tone excitation signals to enhance defect detection in conductive materials. The traditional REC method, which is effective in detecting defects with high spatial resolution, is enhanced by the use of multi-frequency signals to reduce measurement time and provide additional information on defect depth. The proposed method has been tested on an aluminum sample with different defect characteristics, including both superficial and buried cracks. Experimental results demonstrated the effectiveness, in terms of probe sensitivity to the defects, of the novel approach for the different case studies analyzed. The proposed technique provides a comprehensive solution for Non-Destructive Testing (NDT), balancing defect sensitivity, measurement time and defect depth characterization.