Spectra of the 4.5-,µu N<sub>2</sub>O band were obtained after a beam of continuous radiation passed through two cells containing mixtures of N<sub>2</sub>O and N<sub>2</sub>. The total pressure and absorber concentration of one cell were such that its absorption lay essentially in the region where the band absorptance is approximately proportional to the square root of the total pressure and absorber concentration. The total pressure and N<sub>2</sub>O concentration in the second cell were varied over a wide range and two empirical expressions were found relating the total absorptance of the 4.5-µ N<sub>2</sub>O band to the pressures and absorber concentrations of the two cells.
LARRY L. ABELS and JOHN H. SHAW, "Study of the Total Absorptance near 4.5 µ by Two Samples of N2O as Their Total Pressures and N2O Concentrations Were Independently Varied," J. Opt. Soc. Am. 53, 856-859 (1963)