Abstract
The experimental technique for the measurement of thermal diffusivity using the mirage effect, or optical probe beam detection of thermal waves in opaque solids has been described elsewhere. [1–3] This is carried out by scanning the probe beam relative to the heating beam with a constant height, h. The separation, x0, of the two points on either side of the center of such a scan where the phase of the transverse deflection signal reaches ninety decrees effectively measures the thermal wavelength, λ = 2(πα /f)1/2 in the solid. The determination of the thermal diffusivity, a, is accomplished by plotting this separation versus the inverse square root of the frequency. It has been shown theoretically [4,5] that the ratios of the slopes of such plots correspond, in the low frequency limit, to the ratios of the actual diffusivities of the solid. The numerical constant which relates the thermal diffusivity to the slope depends on the value of h. The previous measurements [1–3] of α, carried out using the “skimming” optical probe beam technique (see Fig. 1), were found to be in reasonable agreement with nominal values calculated from handbook data, provided that the slopes of the plots were set equal (heuristically) to (1.0 πα)1/2. Careful examination of the theory [5], however, shows that when h is negligibly small compared to the other characteristics lengths in the experiment, the slope should be (1.4 πα )1/2.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
R.L. Thomas, D.S. Kim, L.D. Favro, P.K. Kuo, C.B. Reyes, and Shu-Yi Zhang. Review of Progress in Quantitative NDE, Vol. 5B, edited by D.O. Thompson and D. Chimenti ( Plenum, New York, 1986 ), 1379.
P.K. Kuo, M.J. Lin, C.B. Reyes, L.D. Favro, R.L. Thomas, D.S. Kim, Shu-yi Zhang, L.J. Inglehart, D. Fournier, A.C. Boccara, and N. Yacoubi, Can. J. Phys. 64(in press).
P.K. Kuo, L.J. Inglehart, E.D. Sendler, M.J. Lin, L.D. Favro, and R.L. Thomas, Review of Progress in Quantitative NDE, Vol. 4B, edited by D.O. Thompson and D. Chimenti (Plenum, New York, 1985), 745.
P.K. Kuo, E.D. Sendler, L.D. Favro and R.L. Thomas, Can. J. Phys. 64 (in press).
J. Jaarinen, C.B. Reyes, I.C. Oppenheim, L.D. Favro, P.K. Kuo, and R.L. Thomas, Review of Progress in Quantitative NDE, Vol. 6, edited by D.O. Thompson and D. Chimenti (Plenum, New York, 1987), (this volume).
Handbook of Chemistry and Physics, 61th Ed., 1980, Chemical Rubber Press (West Palm Beach).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1987 Springer Science+Business Media New York
About this paper
Cite this paper
Reyes, C.B., Jaarinen, J., Favro, L.D., Kuo, P.K., Thomas, R.L. (1987). Reflection-Mirage Measurements of Thermal Diffusivity. In: Thompson, D.O., Chimenti, D.E. (eds) Review of Progress in Quantitative Nondestructive Evaluation. Review of Progress in Quantitative Nondestructive Evaluation, vol 6 A. Springer, Boston, MA. https://doi.org/10.1007/978-1-4613-1893-4_31
Download citation
DOI: https://doi.org/10.1007/978-1-4613-1893-4_31
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4612-9054-4
Online ISBN: 978-1-4613-1893-4
eBook Packages: Springer Book Archive