Measurement of two-dimensional temperature and density distributions by a 2-band-absorption CT. Theoretical investigations.

Efforts to measure the temperature of burnt gases are concentrated mostly on obtaining two- or three-dimensional distributions of the temperature. The authors have developed some methods of computed tomography (CT) with infrared radiation. These methods made it possible to measure two-dimensional distributions of gas temperatures as well as densities of the specie which is active in radiation at the wave length used for the measurement. The characteristics of a 2-band-absorption CT pyrometer are investigated by simulating the reconstructed temperature and density distributions for some model gases. This pyrometer needs no compensation for self-absorption of radiation, though a black body whose temperature is much higher than the gas to be measured is required. The range of temperature to be measured is wider than other CT methods developed by the authors.