Spectral Emissivity of Hydrogen Chloride from 1000–3400 cm^−1*

Abstract

The spectral emissivity of hydrogen chloride from 1000–3400 cm-1 is calculated as a function of temperature, pressure, and amount of radiating gas. The emissivity was calculated with the aid of an electronic computer from the usual expressions for the energy and intensity taking into account up to 2900 spectral lines at 2400°K. The harmonic oscillator approximation was used to evaluate the electric dipole matrix element for the higher vibrational states where no experimental measurements have been made. The emission from HCl35, HCl37, DCl35, and DCl37 was included in the calculation. The statistical model and the random Elsasser model were used to calculate the emissivity from the line strengths. The characteristic shift of the emission to lower frequencies as the temperature increases is quantitatively explained. The emission in this frequency region of any flame containing HCl can readily be obtained from these results.