Thermal Non-destructive Testing and Evaluation is one of the widely used non-destructive inspection methods due to its inherent merits such as remote, full field, safe, and quantitative inspection capabilities for evaluation of wide variety of materials. Among the various thermal non-destructive testing modalities recently proposed matched filter based non-periodic infrared thermographic approaches gained their importance due to their higher test resolution and sensitivity for detection of hidden defects in the test material. Further, feasibility to implement with moderate peak power heat sources in a limited span of time in comparison with conventional thermographic techniques makes these pulse compression favorable techniques more economical and reliable. The present manuscript demonstrates the advantages of pulse compression favorable digitized frequency modulated thermal wave imaging approach for identification of defects in a steel material. The obtained results have been compared with widely used conventional thermographic post processing approaches by taking the signal to noise ratio as a figure of merit.
Keywords
- Matched filter
- Pulse compression
- Frequency modulation
- Infrared thermography