2002 volume 34(5)

Cite as:
Blumm J, Opfermann J, 2002, "Improvement of the mathematical modeling of flash measurements" High Temperatures - High Pressures 34(5) 515 – 521

Improvement of the mathematical modeling of flash measurements

Jürgen Blumm, Johannes Opfermann

Received 12 July 2002, in revised form 12 August 2002

Abstract. The laser flash technique allows measurement of the thermal diffusivity of solids and liquids up to very high temperatures. Various mathematical models have been developed over the past few decades to analyse the experimental data and to remove the influence of the pulse length of the laser and heat loss effects. The most sophisticated model was established by Cape and Lehman (1963 J. Appl. Phys. 34 1909 - 1913) which considers finite pulse effects as well as facial and radial heat losses. For simplification, various assumptions were made in this work to achieve an analytical solution. Improvements of the assumptions were made by other authors such as Jossell et al (1995 J. Appl. Phys. 78 6867 - 6868). Further improvements are proposed here. For accurate pulse-length correction, the original laser pulse is monitored by the hardware and used in the analysis. Furthermore, some improved approximations were integrated into the model. Finally, higher-order solutions of the mathematical description are considered in the analysis. The improved mathematical model is integrated in the nonlinear regression routine, allowing fitting of experimental data to yield thermal diffusivity values with high accuracy.

Restricted material:

PDF Full-text PDF size: 132 Kb

Your computer (IP address: has not been recognised as being on a network authorised to view the full text or references of this article. This content is part of our deep back archive. If you are a member of a university library that has a subscription to the journal, please contact your serials librarian (subscriptions information).