Modelling the optical part of a tomographic system for measuring the gas flow local temperatures

This paper describes a technique for modelling the optical part of a tomographic system for measuring local temperatures of a gas flow. The system is based on the use of a spectral ratio pyrometer. The parameters of the optical part of the tomographic system with a lens part of two configurations are modeled: a single lens and a single lens paired with a microscope objective lens. Diagrams of scattering spots, illumination distributions in the cross section of the beam, and average values of the total radiation power in the focal plane of the optical system are obtained. Recommendations are given for the elimination of parasitic illumination in a pyrometer, as well as for further improvement of the tomographic system lens. (paper)