Absorption of Infrared Radiation by CO_2 and H_2O Experimental Techniques*

The experimental techniques used in an extensive laboratory investigation of the infrared absorption and emission by CO2 and H2O are described. Apparatus discussed include two multiple-pass absorption cells with base lengths of approximately 1 and 29 m, gas-handling systems, a prism spectrometer and a grating spectrometer with their accessories, and a system used to digitize absorption spectra. Also discussed are methods used in gas sampling, checking for possible sources of error, and recording and analyzing the data.