A compact optical fibre based mid-infrared sensor system for detection of high level carbon dioxide emissions in exhaust automotive applications

A highly compact optical fibre based sensor system for real-time measurement of CO2 gas emissions in modern automotive exhaust is reported. The sensing principle is based on extrinsic open-path absorption spectroscopy operating in the mid-infrared wavelength range. The sensing system which comprises of low cost and compact mid-infrared components is suitable for applications in the harsh environment of the vehicle exhaust system. It has been shown that the output of developed sensor system correlates closely with the commercial analyser in respond to high concentrations of CO2 gas. The sensor system also demonstrates minimal susceptibility to cross interferences of other gases present in the exhaust system.