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.