Design and simulation of array eddy current probe based on two orthogonal excitation coils

Pressure equipment is widely used in petrochemical and other industries. However, the pressure equipment is often coated, which brings difficulty to the detection. An array probe based on double tangential eddy current was proposed in this paper, and the performance of the array unit and the overall structure of the array probe were analyzed and designed. The theoretical analysis showed that the proposed array element can eliminate the influence of the direct coupling signal from the excitation coil to the receiving coil. At the same time, since the crack length was only sensitive to the signal peak value, and the crack angle was only sensitive to the peak position, the probe can realize the quantitative analysis of cracks of different lengths and angles at the same time, thus improving the crack detection accuracy. In addition, in order to reduce the lift-off effect on the detection results, the array probe structure with a spring was designed. The spring was always compressed to ensure the minimum lifting of the probe during the detection process. This study can provide technical support for the detection of coated equipment.