A new procedure for measuring thermal properties of solids has been developed on the basis of the principles of laser diagnostics. Modulated laser radiation excites a temperature wave in a sample, which amplitude and phase carry information on the thermal properties of the irradiated region and on the quality of the thermal contact of a coating. Making the probe in the form of a small-sized fiber optic assembly makes it possible to perform manufacturing measurements in the express testing regime. The device allows the inhomogeneity of thermal properties to be determined over an area with a locality up to 0.1 mm.

The designed experimental setup allows a simultaneous readout of information on the parameters of temperature oscillations to be provided from a small area with a spatial resolution of 0.1 mm. The amplitude and the phase of a temperature wave are determined by the variations in the intensity of the laser reflected radiation. The thermal diffusivity in the local parts of a sample is measured by the phase-frequency variation of the Angström method. The method makes it possible to carry out express nondestructive testing of coating quality and examination of thermal properties of new materials under laboratory conditions and in the manufacturing environment.