Gas Identification and Estimation of Its Concentration in a Tube Using Thermographic Camera with Diffraction Grating

The aim of this paper is to demonstrate the application of a reflective diffraction grating and a MWIR thermographic camera for gas identification and its concentration estimation. For this purpose a special setup was built using an infrared camera, a diffraction grating, a black body as infrared source and an air-tight tube that was filled with different mixtures of carbon monoxide, carbon dioxide and nitrogen. Both ends of the tube were closed using infrared transmission windows, allowing the radiation from the blackbody to pass through the tube and be measured with the camera. After spectral calibration of the setup, it was used for the detection, identification and concentration measurements of different gas mixtures.