Combined photopyroelectric-photothermoelectric detection for thermal characterization of liquid thermoelectrics

A new, combined photopyroelectric-photothermoelectric (PPE-PTE) technique, coupled with the thickness scanning (TWRC) procedure, is proposed for thermal characterization of liquid thermoelectrics (LTE). Both pyroelectric and Seebeck effects have been used for this purpose. The PPE-TWRC technique, in back detection configuration leads to the direct measurement of the LTE's thermal diffusivity. Simultaneously, the PTE-TWRC method, in front detection configuration, is used for the measurement of LTE's thermal effusivity. In both cases, the phase of the signal was used as source of information. The main advantage of the proposed technique is an increased accuracy of the results as compared with previously reported procedures. In the meantime, as far as we know, this is the first method proposing a TWRC method applied directly to a sensor itself. The results, obtained on two LTEs, 1-octanol + 10−2 mol/l TDAN (TBAN), are in good agreement with previously reported data.