A Pulse Eddy Current Detection Method for Ferromagnetic Material Defects Based on Orthogonal Vector Magnetic Field Sensors

ABSTRACT The pulsed eddy current method is an indispensable part of non‐destructive testing, capable of effectively detecting defects in ferromagnetic materials and locating the faults. This paper proposes an orthogonal pulsed eddy current detection method considering thermal effects. A 1+3 pulsed eddy current combined coil is designed. A set of directional coils is used as the excitation, and three sets of orthogonal coils are used as the receivers. By collecting the induced signals of the three‐dimensional receiving coils, the relationship between the temperature‐coupled coil output signal and the defect function of the metal component is established. An integrated detection hardware device for transmission‐reception is designed, and conductor plate defect tests are carried out. The tests show that this method can effectively detect metal component defects, expanding the traditional one‐dimensional measurement method to three‐dimensional detection, increasing the available information, and proving the effectiveness and practicality of the new probe.