Inspection of severe service equipment and aging equipment in industry is becoming very important. One of the critical areas
is detection of small surface cracks in metallic components. Even more important is the ability to detect this cracking under
layers of nonmetallic material like insulation.
This paper describes a novel microwave NDE solution that can be used to detect surface cracks with minimal training, no
couplant, and no need for removal of paint and other surface coatings. The inspections can be performed in the field with the
equipment in-place, thus shortening the items out-of-service time. The resulting microwave NDE method is portable and field
deployable with the ability to detect surface cracks in metallic surfaces alone or beneath coatings.
1. Schmidt, K., J. Little and W. Ellingson. “A Portable Microwave Scanning Technique for Nondestructive Testing of
Multilayered Dielectric Materials,” Proceedings of the 32nd International Conference & Exposition on Advanced
Ceramics and Composites. 2008.
2. Schmidt, K., R. Goitia, W. Ellingson and W. Green. “Correlation of Scanning Microwave Interferometry and Digital
X-Ray Images for Damage Detection in Ceramic Composite Armor,” Review or Progress in Quantitative NDE. 2011.
3. Goitia, R., K. Schmidt, J. Little, W. Ellingson, W. Green and L. Franks. “Correlation of Scanning Microwave
Interferometry and Digital X-Ray Images for Damage Detection in Ceramic Composite Armor,” Review or Progress in
Quantitative NDE. 2012
4. Schmidt, K., J. Little, W. Ellingson and W. Green. “Optimizing a Portable Microwave Interference Scanning System for
Nondestructive Testing of Multi-Layered Dielectric Materials,” Review of Progress in Quantitative NDE. 2009.
5. Schmidt, K., J. Little, Jr., W. Ellingson, L. Franks and W. Green. “Optimization of a Portable Microwave Interference
Scanning System for Nondestructive Testing of Multi-Layered Dielectric Materials,” Proceedings of the 34th
International Conference on Advanced Ceramics and Composites, American Ceramics Society. 2010.
6. United States Patent 6,359,446, “Apparatus and Method for Nondestructive Testing of Dielectric Materials,” Mar. 19,
2002.
7. United States Patent 6,653,847, “Interferometric Localization of Irregularities, Nov. 25, 2003.
8. International Patent PCT/US2005/026974, “High-Resolution, Nondestructive Imaging of Dielectric Materials,”
International Filing Date 1 August 2005.
9. Canadian Patent 2,304,782, “Nondestructive Testing of Dielectric Materials,” Mar. 27, 2007.
10. New Zealand Patent 503733, “Nondestructive Testing of Dielectric Materials,” PCT/US2005/026974, International
Filing Date 1 August 2005.
11. Australian Patent 746997, “Nondestructive Testing of Dielectric Materials,” PCT/US2005/026974, International Filing
Date 1 August 2005.