Spectral emissivity of water vapor at 1200°K

Abstract

Results are presented of quantitative spectroscopic studies on pure water vapor in the 1.9-and 2.7-μ regions. Use was made of quartz absorption cells of various lengths, which were heated in an electrical furnace to a temperature of 1200°K. By applying the “statistical” spectral band model at every frequency in each band, it was possible to correlate the observed spectral emissivities with the optical path length and the pressure of the gas. From emissivity measurements in the “linear region” of the 2.7-μ band it was possible to measure the absolute intensity of this band, which was found to be 198 cm −2 atm −1 at 300°K.