Narrow band model parameters for the CO2 4·3 μm band

The narrow band model parameters of the carbon dioxide 4·3 μm band have been obtained from absorption experiments with four broadening gases, namely CO, N₂, O₂, and Ar. The temperature and wave number dependence of the parameters are discussed. The experiments were performed at temperatures of about 303, 598 and 1185°K, with CO₂ partial pressures between 0·01 and 1·0 atm, at a total pressure of 1·0 atm. The Elsasser and the statistical models were applied to thebands in order to obtain applicable parameters and to determine a suitable model for the band at each temperature. It has been found that the Elsasser model is an adequate representation of the band at low temperatures whereas the statistical model is preferred at elevated temperatures. The effect on the line half-widths of the broadening gases is discussed. Good agreement is obtained between absorptance calculated with the present parameters and experimental results obtained by other authors.