Measurements of thermal effusivity of liquids using a conventional photoacoustic cell

In this article, we present a new photoacoustic technique, based on the con ventional photoacoustic configuration, to characterize the thermal effusivi ty of liquid samples. This new technique is applicable for all kind of liqu id samples, including the nontransparent ones. In order to show the usefuln ess of this new technique, we measured the thermal effusivity of a variety of liquid samples including: distilled water, ethanol, methanol, chloroform , glycerol, and car oil. The comparison with literature values shows a rema rkable agreement. Also, we show measurements of the thermal effusivity of a cetone in distilled water mixtures, showing the graphical dependence of thi s thermal property with the concentration of one of the components. (C) 199 9 American Institute of Physics. [S0034-6748(99)01203-4].