Abstract
An experimental investigation has been made into the spectral emission of carbon dioxide, carbon monoxide and mixtures of these gases. The wavelength regions investigated were 2.1 to 3.2 microns and 3.9 to 5.0 microns. Temperature and pressure ranges were respectively 500 to 900°C and 35 k to 700 kPa. A static gas sample was held under isothermal conditions in a metal test cell fitted with infra-red transmitting windows. The test cell was located inside a water-cooled pressure vessel filled with dry nitrogen that was automatically maintained at the-same pressure as the test gas. Emitted radiation from the hot gas passed through a window in the pressure vessel and was measured by a reflection-type grating spectrometer. The signal from the detector was amplified fed to the recording equipment. The test cell was of a novel design that allowed complete calibration to be made for each emissivity measurement. This is an inherent improvement in measurement technique over other methods used by other Worker In this way, only variations in the system that occurred during the measurement were significant. Spectral emissivities were computed from ratios of relative emissive powers obtained from the test cell. Corrections were applied to allow for temperature fluctuations during a measurement. Spectral emissivity data are presented and these are compared with published experimental data.