PHOTOTHERMAL RADIOMETRY APPARATUS USING PSEUDORANDOM EXCITATION FOR NONDESTRUCTIVE EVALUATION OF LAYERED MATERIALS

The characterization of thermal systems under unsteady regime is mostl y carried out under pulsed or sinusoidal excitation, as they are easie r to produce, analyze, and model, The new means of study offered by op tics and computers now allow us to operate and exploit other modes of thermal analysis of systems. The equipment presented uses random type excitation and is to be applied to nondestructive testing. Yet, the sc ope of this method can be enhanced. In fact, it can be tied to differe nt means of thermal stimulation as well as to various types of sensors . It can be more generally used for the analysis of different thermal systems under unsteady regime.