Application of a superconductor to the shield of a remote field eddy current testing probe

摘要

This paper proposes the application of a superconductor to a remote field eddy current testing probe in order to shorten the probe length and then overcome many of the disadvantages of the remote field eddy current testing, such as the small signal amplitude and the difficulty in handling the probes, Numerical simulations were carried out to confirm that a superconductor located between the exciter and the detector of a remote field eddy current testing probe inhibits the magnetic flux from coming directly from the exciters. Then, a remote field eddy current testing probe equipped with a superconducting shield was designed and fabricated. Experimental results confirmed that a superconducting shield can shorten the probe length and provide clearer signals due to artificial wall thinnings machined on the outside surface of a ferromagnetic tube.