We develop a dimensionless heat transfer model to analyze pulsed thermography data for non-destructive testing (NDT) of materials. Simulated thermographic sequences are used in order to evaluate the performance of the inspection technique. Also, we inspect organic and inorganic samples, including a layered plate and two dental pieces, in search of internal defects and structural inhomogeneities. We detect cavities and the inner structure of the samples by means of reconstructed thermograms and a modified version of the differential absolute contrast (DAC). Moreover, we develop an effective data compression method that reduces a thermographic video with m frames of p × q pixels to two matrices of p × q elements. In this data reconstruction process, precision and compression ratio are independent parameters. Finally, we find that partial translucency of dental enamel, in infrared, permits imaging of the internal structure of a tooth. This inspection technique does not require a priori knowledge about a reference defect-free area.
We determine the temperature distribution within the flame as a function of position. We determined temperature
distribution and the length of a flame by dual-wavelength thermometry, at 470 nm and 515 nm. The error percentages on
the temperature and the flame length measurements are 1.9% as compared with the predicted thermodynamic results.