A Novel Deep Penetrating Eddy Current Probe for Inspection of Deep Cracks in SUS304

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