Thermal diffusivity measurements in vegetable oils with thermal lens technique

Using a thermal lensing experimental setup the thermal properties of several vegetable oils were obtained. The samples were oils from Amazonian species and olive (the popular identifications are piqui, copaiba, buriti, and babaçu). The two lasers mismatched mode experimental configuration was used, with a He–Ne laser as the probe and an Ar+ laser as the excitation one. The time resolved spectra were measured using an automatic system, and fitting the aberrant theoretical model to the data, the characteristic relaxation time were obtained, and knowing this value, the thermal property of each oil was solved.