Long Path Water Vapor Spectra with Pressure Broadening I 20 μ to 317 μ*

Abstract

There is in progress an experimental study of the meteorologically important 50 μ pure rotation band of water vapor. Transmission through a 196-m path under a range of known conditions of water concentration and of nitrogen pressures is measured. This first paper reports transmission spectra for the region 20 μ to 31.7 μ at a resolution of about 4 cm−1. The water vapor partial pressure ranges from 0.02 to 0.7 cm Hg and the nitrogen partial pressure from 0 to 60 cm Hg. The method for sample analysis is indicated and the importance of adsorption effects demonstrated.