Knowledge Bank

The contour of isolated Lorentz lines (under the conditions: $(Su\gamma )>\pi 4$ conforms closely to the universal transmission contour (UTC): $A=e-\pi /x2$ where $x=\pi (p-poS\gamma u)$ Also, the transmission contour is adequately, and for some purposes conveniently, represented for x $\ge$ 1.0, by the polynomial {A}=\pi\left(\frac{1}{{x}^{2}}-\frac{1.358}{{x}^{4}}+\frac{0.6762}{{x}^{6}}\right) The conditions of the UTC are more than met for several strong lines in the 6$\mu$ water band when they are measured at low pressures (as in our ONR, long-path (92M) absorption cell). New analyses yielding $S\gamma$ values for 6$\mu$ pure water vapor lines thus observed will be presented: as well as conventional analysis of observations of the same lines under short-path high-pressure conditions---this time yielding S/$\gamma$ values. Special features and several advantages of the new analysis procedures will be discussed. Also, new procedures of observation suggested by the UTC will be presented, particularly procedures applicable to monitoring polyatomic pollutant gases in the atmosphere.