Analysing the composition of a gas is a complex challenge. Depending on the use case and considering thermodynamic constraints such as gas temperature, gas pressure, and flow rate, various technologies are available. Specific sensors are usually straightforward to use. However, they often have limited concentration ranges and require more or less complex calibration. More sophisticated techniques, such as mass and absorption spectroscopy or gas chromatography, each have their own limitations. Some require ambient pressure, dedicated probe extraction, or time-consuming analysis processes. Raman spectroscopy appears to overcome many of these limitations. However, the Raman effect is so weak that complex and expensive setups are required. To overcome these problems, Bosch developed the BOGS (Bosch Optical Gas Spectrometer). Raman gas spectroscopy is now extremely easy. Gas concentrations as low as 100 ppm can now be detected, and even lower concentrations when the pressure is higher (up to 40 bar) and the detection time is increased from seconds to minutes.
A. Stratmann (Thu,) studied this question.