Hidden Crack Detection with GMR Sensing of Magnetic Fields from Eddy Currents

Journal Article · Wed Mar 21 00:00:00 EDT 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2717983· OSTI ID:21054965

Ko, Ray T; Sathish, Shamachary ^[1]; Knopp, Jeremy S; Blodgett, Mark P ^[2]

---

1. Structural Integrity Division, University of Dayton Research Institute, 300 College Park Drive, Dayton, Ohio 45469-0120 (United States)
2. Metals, Ceramics, and NDE Division, Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

A giant magneto-resistive (GMR) sensor placed inside a coil has been used for same side eddy current measurements on metallic plates. Magnetic fields from eddy currents generated in these metallic plates by excitation of the coil, are detected by the GMR sensor. The signal excitation and detection is accomplished using a lock-in amplifier which allows independent measurement of the phase and magnitude. The sensor configuration has been used to detect notches. Phase and magnitude images acquired with this sensor configuration are compared with the images obtained using the coil only.

• OSTI ID: 21054965
• Journal Information: AIP Conference Proceedings, Vol. 894, Issue 1; Conference: Conference on review of progress in quantitative nondestructive evaluation, Portland, OR (United States), 30 Jul - 4 Aug 2006; Other Information: DOI: 10.1063/1.2717983; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALLOYS
CRACKS
DETECTION
EDDY CURRENT TESTING
EDDY CURRENTS
EXCITATION
IMAGES
LOCK-IN AMPLIFIERS
MAGNETIC FIELDS
MAGNETORESISTANCE
PLATES
SENSORS