Abstract
In this paper, a video-based speckle interferometric method using a continuous reference updating technique is presented. Unlike conventional ESPI techniques, this methodsynchronizes the optical interferometric detection system with the acoustic stressing of the test object, and includes continuous renewal of the reference image. It is shown that the susceptibility of the method to environmental noise caused by vibration, temperature gradients, or thermal currents is substantially lower than that of conventional techniques. The application of this technique to the detection of defects in adhesively bonded structures is demonstrated.
Similar content being viewed by others
References
D. D. Burleigh, Shearographic NDT of Foam Insulation for Cryogenic Fuel Tanks, Spring Conference of the American Society for Nondestructive Testing, March 30–April 3, 1992, Orlando, Florida.
J. F. Clarady, Electronic Holography and Shearography NDE for Inspection of Modern Materials and Structures, Spring Conference of the American Society for Nondesctructive Testing, March 30–April 3, 1992, Orlando, Florida.
O. J. Lokberg, ESPI—The ultimate holographic tool for vibration analysis?J.A.S.A. 75(6):1783 (1984).
K. Creath and G. A. Slettemoen, Vibration observation techniques for digital speckle pattern interferometryJ. Opt. Am. A 2(10):1629 (1985).
R. Jones and C. Wykes,Holography and Speckle Interferometry (Cambridge University Press, 1989).
S. Nakadate, T. Yatagai, and H. Saito, Electronic Speckle Pattern Interferometry Using Digital Image Processing Techniques,Appl. Opt. 191879 (1980).
O. J. Lokberg, O. M. Holje, and H. M. Pederson, Scan converter memory used in TV-speckle interferometry,Opt. Laser Technol 817 (1976).
C. C. Aleksoff, Temporally modulated holography,Appl. Opt. 10(6):1329 (1971).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pouet, B., Chatters, T. & Krishnaswamy, S. Synchronized reference updating technique for electronic speckle interferometry. J Nondestruct Eval 12, 133–138 (1993). https://doi.org/10.1007/BF00567569
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00567569