Magnetic Shielding Analysis for Arrayed Eddy Current Testing

Arrayed eddy current testing (AECT) has been widely applied in the field of crack detection, displacement measurement and many other fields due to its non-destructive and high efficiency. But the coupling interference of AECT exists objectively and leads to the detection error directly. In this paper, a magnetic shielding layer is proposed to reduce the coupling interference. The relationships between electromagnetic parameters of magnetic shielding material and coupled magnetic field are discussed theoretically. Furthermore, the simulation and experiments are carried out, the results are consistent. It shows that the application of magnetic shielding layer in AECT can reduce the mutual inductance of probe coils and increase the output voltage. Additionally, the most important factor to select material of magnetic shielding layer is the conductivity. Thus, the magnetic shielding layer with large conductivity will be suitable for AECT to promote the testing performance.