TY - CONF A1 - Altenburg, Simon A1 - Bernegger, Raphael A1 - Krankenhagen, Rainer T1 - Analytical modelling of semitransparent solids for flash thermography with absorption coefficient dispersion N2 - Pulse and flash thermography are experimental techniques which are widely used in the field of non-destructive evaluation for materials characterization and defect detection. We recently showed that it is possible to quantitatively determine the thickness of semitransparent polymeric solids by fitting of results of an analytical model to experimental flash thermography data, for both transmission and reflection geometry. However, depending on the chosen experimental geometry, different effective optical absorption coefficients (i.e., penetration depths of the heating light) had to be utilized in the model in order to properly fit the experimental data. Here we show that this effect is caused by the wavelength dependency of the absorption coefficient of the sample material. We present an extension of the analytical model to incorporate this dispersion. Even accounting for only two different values of the absorption coefficient, the experimental results from both measurement geometries can be fitted by a single set of absorption coefficients. Additionally, the deviations between experimental data and fit are reduced compared to a single optimized effective absorption coefficient. This work is part of the ZIM-project KF2201089AT4 and is funded by the German Federal Ministry for Economic Affairs and Energy due to an order of the German Bundestag. T2 - 19th International Conference on Photoacoustic and Photothermal Phenomena CY - Bilbao, Spain DA - 16.07.2017 KW - Analytical model KW - Semitransparency KW - Thermography PY - 2017 AN - OPUS4-41084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -