A novel deep penetrating eddy current probe based on phase shifted fields and its application to inspection of defects

Abstract

Due to the skin effect of eddy currents, the depth of cracks which can be detected by the traditional eddy current probe is very limited. In order to improve the ability of eddy current probes to inspect deep cracks in metal thick-walled structures, a new eddy current probe using an excitation system with phase shifted fields was proposed. Its feasibility for detecting deep cracks was verified by simulation and experiments. The results showed that the penetration depth of eddy currents in austenitic stainless steel is effectively enhanced by using the new probe.

Keywords

• skin effect
• penetration depth
• austenitic stainless steel
• eddy current probe
• phase shifted fields