Theoretical Description Of The Photopyroelectric Technique In The Slanted Detector Configuration For Thermal Diffusivity Measurements In Fluids

This work presents an extended description about the theoretical aspects related to the generation of the photopyroelectric signal in a recently proposed wedge-like heat transmission detection configuration, which recreates the well-known Angstrom method (widely used for solid samples) for accurate thermal diffusivity measurement in gases and liquids. The presented model allows for the calculation of the temperature profile detected by the pyroelectric sensor as a function of the excitation beam position, and the study of the influence on it of several parameters, such as spot size, thermal properties of the absorber layer, and geometrical parameters of the measurement cell. Through computer simulations, it has been demonstrated that a narrow temperature distribution is created at the sensor surface, independently of the lateral diffusion of heat taking place at the sample's surface. © 2014 Elsevier B.V.582101105Almond, D.P., Patel, P.M., (1996) Photothermal Science and Techniques in Physics and Its Applications, 10 VOL.. , Chapman and Hall LondonMarín, E., Vargas, H., Recent developments in thermal wave interferometry (2009) Thermal Wave Physics and Related Photothermal Techniques: Basic Principles and Recent Developments, pp. 99-123. , Transworld Research Kerala, IndiaChirtoc, M., Mihilescu, G., Theory of the photopyroelectric method for investigation of optical and thermal materials properties (1989) Phys. Rev. B, 40, pp. 9606-9617Chirtoc, M., Chirtoc, I., Bicanic, D., Pelzl, J., Photopyroelectric (PPE) spectroscopy: Absorption, transmission or reflection? (1995) Ferroelectrics, 165, pp. 27-38Mandelis, A., Matvienko, A., Photopyroelectric thermal-wave cavity devices-10 years later (2007) Pyroelectric Materials and Sensors, Research Signpost, pp. 61-97. , Kerala, IndiaAngstrom, A.J., A new method to determine the heat conduction capacity of physical objets (1861) Ann. Phys. Lpz., 114, pp. 513-530Marin, E., Jean-Baptiste, L.E., Hernandez, M., Teaching thermal wave physics with soils (2006) Revista Mexicana de Fisica, 52 (1 SUPPL.), pp. 21-27Rojas-Trigos, J.B., Bermejo Arenas, A., Marín, E., On heat transfer through a solid slab heated uniformly and periodically: Determination of thermal properties (2012) Eur. J. Phys., 33, pp. 135-148Kuo, P.K., Favro, L.D., A simplified approach to computations of photoacoustic signals in gas-filled cells (1982) Appl. Phys. Lett., 40 (12), pp. 1012-1014Fabbri, L., Cernuschi, F., Finite laser beam size effects in thermal wave interferometry (1997) Journal of Applied Physics, 82 (11), pp. 5305-5311Salazar, A., Mendioroz, A., Propagation of thermal waves across a wedge (2012) J. Appl. Phys., 112, p. 063511Marín, E., Hernández-Rosales, E., Mansanares, A.M., Ivanov, R., Rojas-Trigos, J.B., A method for thermal diffusivity measurement in fluids (2013) Rev. Sci. Instrum., 84, p. 104903Mandelis, A., (2001) Diffusion-Wave Fields. Mathematical Methods and Green Functions, , Springer Verlag New YorkTouloukian, Y.S., Powell, R.W., Ho, C.Y., Nicolau, M.C., (1973) Thermal Diffusivity, , IFI New YorkKallaev, S.N., Gadzhiev, G.G., Kamilov, I.K., Omarov, Z.M., Sadykov, S.A., Reznichenko, L.A., Thermal properties of PZT-based ferroelectric ceramics (2006) Physics of the Solid State, 48 (6), pp. 1169-1170. , DOI 10.1134/S1063783406060473Hooker, M.W., (1998) Properties of the PZT-Based Piezoelectric Ceramics between -150 and 250 °c, (NASA CR-1998-208708), , Lockheed Martin Engineering & Sciences Co. Hampton, V