Line-of-sight absorption measurements of high temperature gases with thermal and concentration boundary layers

The effect of thermal and concentration boundary layers on experimental data must be well understood for a successful diagnostic measurement of quasi-uniform high-temperature gases using line-of-sight absorption spectroscopy. In this paper, an energy-temperature curve is proposed to assist in selection of candidate absorption lines. Two techniques, the effective absorption path length method and the direct curve-fit method, are proposed to extract absolute concentrations from absorption data obtained in the presence of boundary layers.

Reliable and efficient program for fitting Galatry and Voigt profiles to spectral data on multiple lines

Experimental data with multiple overlapping spectral lines must often be fitted to theoretical line shape models. This paper describes an efficient program for performing least-squares fits of such data to Galatry and Voigt profiles. The algorithm and program design considerations are presented in detail, and some examples are given to demonstrate its use. The procedure described in this paper may also be used for more complex line shape profiles.