Journal of the Korean Society for Nondestructive Testing (비파괴검사학회지)

The Korean Society for Nondestructive Testing (한국비파괴검사학회)
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A Study on the Optimized Test Condition of Lock-in IR Thermography by Image Processing

  • Cho, Yong-Jin (Department of Naval Architecture and Ocean Engineering, Dong-Eui University)
  • Received : 2012.05.02
  • Accepted : 2012.06.15
  • Published : 2012.06.30
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Abstract

In this study, it was studies the utilization of LIT(lock-in infrared thermography) which can detect defects in welded parts of ship and offshore structures. Quantitative analysis was used through methods of filtering and texture measurement of image processing techniques to find the optimized experimental condition. We verified reliability in our methods by applying image processing techniques in order to normalize evaluations of comparative images that show phase difference. In addition, low to mid exposure showed good results whereas high exposure did not provide significant results in regards to intensity of light exposure on surface. Lock-in frequency was satisfactory around 0.1 Hz regardless of intensity of light source we had. In addition, having the integration time of thermography camera inversely proportional to intensity of exposed light source during the experiment allowed good outcome of results.

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References

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  2. A Taguchi Design of Experiment Approach to Pulse and Lock in Thermography, Applied to CFRP Composites vol.36, pp.4, 2017, https://doi.org/10.1007/s10921-017-0450-4