Detection of subsurface flaws using SQUID eddy current technique

Yu Pei Ma; John P. Wikswo Jr.

doi:10.1117/12.163843

3 December 1993 Detection of subsurface flaws using SQUID eddy current technique

Yu Pei Ma, John P. Wikswo Jr.

Proceedings Volume 2001, Nondestructive Inspection of Aging Aircraft; (1993) https://doi.org/10.1117/12.163843
Event: SPIE's 1993 International Symposium on Optics, Imaging, and Instrumentation, 1993, San Diego, CA, United States

Abstract

Subsurface flaws in electrically conducting components are not easy to detect by conventional eddy current techniques because the skin depth (delta) decreases at high frequencies, while the signal decreases at low frequencies. However, SQUID magnetometers are capable of measuring dc and low frequency magnetic fields, and have been used for imaging current distributions. We have now extended SQUID NDE by utilizing a technique to induce an extended eddy current parallel to the surface in a conducting plate. The magnetic field due to the eddy current perturbation caused by a subsurface flaw has been calculated and compared with experimental results, which gives information about the depth of the flaw. We also present data recorded from aluminum samples that simulate lap joints in aircraft wings.

Citation Download Citation

Yu Pei Ma and John P. Wikswo Jr. "Detection of subsurface flaws using SQUID eddy current technique", Proc. SPIE 2001, Nondestructive Inspection of Aging Aircraft, (3 December 1993); https://doi.org/10.1117/12.163843

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available