The strong influence of heat losses on the accurate measurement of thermal diffusivity using lock-in thermography

Salazar, Agustín; Mendioroz, Arantza; Fuente, Raquel
September 2009
Applied Physics Letters;9/21/2009, Vol. 95 Issue 12, p121905
Academic Journal
In modulated photothermal experiments the lateral thermal diffusivity can be obtained from the slope of the linear relation between the phase of the surface temperature and the distance to the heating spot. However, this slope is greatly affected by heat losses so that the measured thermal diffusivity is overestimated, especially for thin samples of poor thermal conducting materials. In this paper we definitely identify the physical mechanism responsible for the overestimation of the diffusivity as heat conduction to the surrounding gas. Accurate measurements of the thermal diffusivity using the “slope method” have been obtained by keeping the sample in vacuum.


Related Articles

  • Simultaneous measurement of thermal diffusivity and optical absorption coefficient using photothermal radiometry. I. Homogeneous solids. Fuente, Raquel; Apiñaniz, Estibaliz; Mendioroz, Arantza; Salazar, Agustín // Journal of Applied Physics;Aug2011, Vol. 110 Issue 3, p033515 

    Modulated photothermal radiometry (PTR) has been widely used to measure the thermal diffusivity of bulk materials. The method is based on illuminating the sample with a plane light beam and measuring the infrared emission with an infrared detector. The amplitude and phase of the PTR voltage is...

  • New methodology for thermal parameter measurements in solids using photothermal radiometry. Depriester, M.; Hus, P.; Delenclos, S.; Sahraoui, A. Hadj // Review of Scientific Instruments;Jul2005, Vol. 76 Issue 7, p074902 

    The photothermal radiometry (PTR) signal is analyzed in order to simultaneously obtain the thermal diffusivity and effusivity of solid materials. Analytical procedures that allow the determination of the thermal parameters via a frequency scan of the amplitude or the phase of the PTR signal are...

  • Method for thermal diffusivity measurements based on photothermal deflection. Bertolotti, M.; Liakhou, G.; Li Voti, R.; Michelotti, F.; Sibilia, C. // Journal of Applied Physics;12/15/1993, Vol. 74 Issue 12, p7078 

    Presents information on a study which discussed the thermal diffusivity measurement through pulsed photodeflection in a modified collinear configuration. Methods; Results; Discussion.

  • Measurement of thermal diffusivity at high pressures and temperatures using synchrotron radiography. D. P. Dobson; S. A. Hunt; L. Li; D. Weidner // Mineralogical Magazine;Apr2008, Vol. 72 Issue 2, p653 

    A new method to measure thermal diffusivity in samples at simultaneous high pressure and high temperature is presented. The sample is placed inside a cylindrical heater and subjected to a heater power that varies sinusoidally with time. The diffusion of the temperature variations into the sample...

  • Development of photothermal-resistance technique and its application to thermal diffusivity measurement of single-wall carbon nanotube bundles. Hou, J.; Wang, X.; Liu, C.; Cheng, H. // Applied Physics Letters;5/1/2006, Vol. 88 Issue 18, p181910 

    In this work, a photothermal-resistance technique is developed to characterize the thermophysical properties of one-dimensional micro/nanostructures. In this technique, a periodically modulated laser beam is used to achieve noncontact heating of suspended individual wires. The temperature...

  • Spatially localized measurement of thermal conductivity using a hybrid photothermal technique. Hua, Zilong; Ban, Heng; Khafizov, Marat; Schley, Robert; Kennedy, Rory; Hurley, David H. // Journal of Applied Physics;May2012, Vol. 111 Issue 10, p103505 

    A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k = (e2/D)1/2. To generalize this approach,...

  • A NEW DEFINITION OF BEJAN NUMBER. AWAD, Mohamed M. // Thermal Science;2012, Vol. 16 Issue 4, p1251 

    A new definition of Bejan number will be generated by replacing the thermal diffusivity with the mass diffusivity.For example, the Schmidt number is the mass transfer analog of the Prandtl number. For the case of Reynolds analogy (Sc = Pr = 1), both current and new definitions of Bejan number...

  • Thermal diffusivity of iron at high temperatures. Gorbatov, V.; Polev, V.; Korshunov, I.; Taluts, S. // High Temperature;Apr2012, Vol. 50 Issue 2, p292 

    The results of the thermal diffusivity measurements for pure iron within the temperature range from 830 K up to 1820 K obtained in automated mode by the dynamic plane temperature wave method have been presented.

  • The errors in determining the thermal characteristics of semitransparent materials by a pulse method. Kuznetsov, G.; Katz, M. // Measurement Techniques;Dec2012, Vol. 55 Issue 9, p1057 

    The errors in determining the thermal characteristics of a semitransparent material by a pulsed method are determined by comparing the results of a numerical solution of the problem of the steady temperature field of a sample when a collimated laser pulse of finite duration acts on its surface...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics