Pressure-broadened linewidths of the R(9.5)(3/2) NO transition

Pressure-broadened ir linewidths of nitric oxide are currently used in measurement of its concentration for studies on combustion, chemical kinetics, and air pollution.(1) We have measured the self-broadened width of the R(9.5)(3/2) transition in the NO fundamental band by CO laser transmittance and found a halfwidth of gamma = 0.0783 +/- 0.0067 cm(-1) atm(-1). The analysis is shown to depend on the treatment of A-doubling, even though the doublet spacing is less than the Doppler width. The foreign gas broadening by N(2) of this transition is similarly measured, and the ratio of self-broadening ability to the broadening ability of N(2) is found to be 1.30 +/- 0.31.