Thermal Diffusivity Measurement of Liquid Samples by Inverse Photopyroelectric Detection

Abstract

This paper describes a new method for measuring the thermal diffusivity of liquid samples through inverse photopyroelectric detection measurement. It is proven that thermal diffusivity values can be obtained with both amplitude signals and phase signals in a low frequency range. At around 3 Hz, these values are found to correspond to their theoretical values. We experimentally prove that the piezoelectric effect, which films are known to exhibit, is negligibly small compared with the photopyroelectric effect.

High-Precision and High-Resolution Measurements of Thermal Diffusivity and Infrared Emissivity of Water–Methanol Mixtures Using a Pyroelectric Thermal Wave Resonator Cavity: Frequency-Scan Approach

“…Among other mixtures, water-alcohol solutions are of special interest, mostly in chemical, food, and environmental applications. Up to now, a variety of techniques have been employed for the measurement of the thermal diffusivity of alcohols and water-alcohol mixtures [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Photon correlation spectroscopy has been used in measurements of pure alcohols and their binary mixtures [1,2].…”

“…Overall, the lowest concentration of alcohol in water measured in the aforementioned works was always greater than 10% v/v. More recently, photopyroelectric methods have been successfully employed for accurate and precise measurements of thermal diffusivity [8][9][10][11][12][13]. A common application of these techniques lies in monitoring the behavior of the thermal-wave field generated in a liquid using photopyroelectric sensors.…”

Photopyroelectric Microscopy Based on Pb0.88La0.08Ti0.98Mn0.02O3Ferroelectric Ceramics

“…This deformation could add a piezoelectric effect in the measurement and then the theoretical modeling would become more complicated, a way to limit the sensor deformation is by the substrate use in which the sensor is fixed, like acrylic resin and silicon oxide plates (SiO 2 ) [2][3][4][5]. A ferroelectric ceramic was proposed as pyroelectric sensor in order to avoid a possible piezoelectric effect in the measurements due to its hardness.…”

Perspective: Photopyroelectric effects and pyroelectric measurements: “Invited Review Article: Photopyroelectric calorimeter for the simultaneous thermal, optical, and structural characterization of samples over phase transitions” [Rev. Sci. Instrum. 82, 121101 (2011)]

“…A significant advancement appeared with the reverse photopyroelectric modification of the original configuration. 9 In this configuration, light impinges directly on the surface of the pyroelectric sensor, which is in contact with the sample on its other side. A comprehensive discussion of PPE applications can be found in the literature.…”

“…The work by Dadarlat et al 9 on PPE studies of ferroelectric materials is seminal as it addresses the relevance of the measurement of their thermal parameters for evaluating the figure of merit of IR sensors 29 or pyroelectric accelerators. 30 When the pyroelectric element is used as a sensor in a PPE experiment, knowledge of these parameters is crucial, because other measured properties depend of these values and, conversely, characterization of pyroelectric detectors using the photopyroelectric technique 31 adds much desired consistency and a wealth of sensor information to the PPE measurement.…”