3D Magnetic Field Responses to a Defect Using a Tangential Driver-coil for Pulsed Eddy Current Testing

In Pulsed Eddy Current (PEC) testing, the response feature of one-dimensional magnetic field component, perpendicular to the conductor’s surface, is used to detect and quantify the defects. It is not sufficient for signal interpretation and noise suppression. A novel PEC probe, which consists of a tangential driver-coil and three orthorhombic pickup coils, is introduced in this paper. It is greatly advantageous to realize three dimensional field components measurement independently. Moreover it is characteristic of self-difference and lower lift-off noise. Using Finite Element Method (FEM), three dimensional magnetic flux density responses due to a defect in conductor plate, have been calculated. The result shows that a defect’s depth and edges can be evaluated quantitatively by extracting three dimensional field components responses features. Numerical predication is in good agreement with experimental measurement. These merits are valuable for imaging inspection of defects (such as corrosion, dent, rivet hole, etc) in the aircraft