Multicomponent fiber optic gas sensor based on MIR tunable diode lasers

Within the framework of this studies development of a model of a functional multicomponent highly sensitive new generation analyzer, designed to measure 2 to 4 gas components in a mixture, was proposed. This model will become a prototype for a whole new family of analyzers, which will differ from one another by their particular set of detected gases and sensitivity depending on task requirements. The gas detecting analyzers utilise the principles of high resolution absorption spectroscopy, possibly by utilising a tunable diode lasers (TDL) in the IR range. By using a laser spectral method for measuring, it ensures high sensitivity, accuracy, selectivity and fast time response in recording. The distinguishing aspect in the development of the analyzer is the design and schematic based on the use of MIR-fiber optics with low optic losses. Hence, it is possible to have the unit in a small geometric volume with instrumentation for a multichannel measuring optical track, and a simplified cryostatic system for IR lasers and photodetectors. With the help of a highly sensitive, fast tune responding analyzer based on tunable diode lasers, molecular gases, having absorption bands in the IR range, can be measured. Detection of molecules like CO, CO2, NO, NO2, N20, H2S, SO2, NH3, H20, H2O2, CH4, C2H2, C2H4, HF, HC1, HCN, freons and many others is possible using this technique. These multicomponent gas sensors can be applied as a diagnostic tool in scientific investigations, in physics, chemistiy and biochemistry, in ecology - for recording atmospheric pollutants, in medicine - diagnosing illnesses and screen tests as well as in industiy - trace chemical technology and burning processes. These systems can be also used as a reference tool for calibration of less sensitive and less precise gas analyzers used in routine monitoring.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.