Simple modelling of Q-branch absorption-III. Pressure, temperature, and perturber dependences in the 2v₆ Q-branch of ¹²CH³⁵ClF₂ (HCFC-22)

The simple approach developed in a previous paper in order to model absorption by Q -branches is applied to the 2v₆ Q-branch of ¹²CH³⁵ClF₂ (HCFC-22). Measurements have been made using a tunable diode laser for pure HCFC-22 and mixtures with N₂ and O₂. The pressures and temperatures investigated, which are suitable for atmospheric applications, range from 0.05 to 1.0 atm and from 200 to 300 K, respectively. It is shown that our model enables satisfactory prediction of both the pressure, temperature, and wavenumber dependences of absorption with eleven effective parameters which have been deduced from measured spectra. Their values are in satisfactory agreement with results from other sources. The model proposed can also accurately predict spectra measured by other authors as well as correctly compute atmospheric transmission.