Real time exhaust gas sensor with high resolution for onboard sensing of harmful components

Emission control and reduction of harmful gases produced by combustion engines is a very important task. There is need for a high resolution online detection of harmful gases. This work presents a novel optical sensor system based on newly developed LEDs working in the ultraviolet and visible wavelength range. The developed potentially low cost LED based system is able to individual detect NO₂ and SO₂ with high resolution (1 ppm), wide measurement range (some 1000 ppm) and temporal dynamic of up to 10 ms (stroke resolution). Fiber optics are applied to a robust free path absorption cell to resist the harsh tailpipe environment and enable the online measurement of hot gases.