A remote field eddy current NDT probe for the inspection of metallic plates

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Materials Evaluation

DOI:https://doi.org/10.1007/978-1-4613-0383-1_148· OSTI ID:227925

Sun, Y S; Udpa, S; Lord, W; Cooley, D ^[1]

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1. Iowa State Univ., Ames, IA (United States). Dept. of Electrical and Computer Engineering

The remote field eddy current (RFEC) technique was invented in 1951 and is widely used as a nondestructive evaluation tool for inspecting metallic pipes and tubing. Essentially, the RFEC phenomenon can be observed when an AC coil is excited inside a conducting tube. The RFEC signal can be sensed by a pick-up coil located two to three diameters away from the excitation coil. The signal is closely related to the tube wall condition, thickness, permeability, and conductivity. For tubing inspection, the RFEC technique is characterized by its equal sensitivity to an inner diameter (ID) or an outer diameter (OD) defect, its insensitivity to probe wobble or lift-off, and for not being limited by the penetration depth, which has traditionally been a major disadvantage for conventional eddy current techniques, especially in ferromagnetic material inspection. However, RFEC applications have been restricted to inspection of metallic tubing, although there are demands for accurate and fast inspection for some flat-shaped metals, such as tank bottoms and vessel walls. Can the RFEC technique be extended to the inspection of metallic plates? This paper shows that the RFEC phenomenon can also be observed in planar metallic plates.

• Sponsoring Organization: USDOE
• OSTI ID: 227925
• Journal Information: Materials Evaluation, Journal Name: Materials Evaluation Journal Issue: 4 Vol. 54; ISSN MAEVAD; ISSN 0025-5327
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
COMPUTERIZED SIMULATION
EDDY CURRENT TESTING
EXPERIMENTAL DATA
METALS
PLATES
PROBES
THEORETICAL DATA