Non -destructive testing (NDT) of materials can be achieved via proper photonic excitation and radiometric monitoring of the induced thermal changes. The theoretical support for this photothermal conversion in bi-layered materials is proposed, single -pulse and periodically modulated fluxes being considered. Some practical proposals are derived concerning the various aims of NDT: coatings thickness measurements, detection of defective bondings or delaminations, measurements of contact resistances between two layers. Measurements performed with a commercially available infra -red scanner and a digital data acquisition and processing system are reported.

Whole blood is an inhomogeneous, thermally fragile liquid suspension. It was shown that photothermal radiometry yields meaningful results, but required irradiation level might disturb the sedimentation process. Despite the necessity for direct contact, photopyroelectric method is more sensitive and also easier and cheaper to implement for routine measurements. All the experimental results are in a good agreement with developed theoretical models.

Using a mobile photothermal probe we show that it is possible to detect rapidly different type of cracks (emerging ones or not), their width being a few micrometers and their depth being some hundredths of micrometers

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