This might soon be possible according to researchers at the University of Manchester. They've designed a near-infrared diode laser sensor able to record levels of carbon dioxide, carbon monoxide and methane directly from your car's exhaust. Their device could be one day incorporated into onboard diagnostic systems and be permanently in use while you drive. So you could be warned that your pollution levels are too high. The system would include dashboard warnings telling you to modify the way you're driving.
This system has been developed by Dr Philip Martin of the School of Chemical Engineering and Analytical Science (CEAS) at The University of Manchester, with the help of his colleagues Yvan Gérard and Robert Holdsworth. On the left, you can see the static engine test bed the researchers used to take their measurements. (Credit: Image courtesy of University of Manchester) [Note: I've picked this image on this page at ScienceDaily because the University of Manchester's Media Relations Officer is on vacation until August 15. So I was unable to get other pictures.]
Anyway, the researchers acknowledge that their system is not ready yet for prime time. But "once optimised, the process could be incorporated into onboard diagnostic systems that would monitor emissions as vehicles drive along -- and potentially help people reduce their emissions by adjusting their driving style."
So far, in a Ministry of Transport test, "exhaust emissions are extracted into a box while the engine is idling and the gases present are then measured. 'This is the first instance of this type of near-IR diode laser sensor being used directly in the exhaust of a static internal combustion engine to measure emissions, said Martin."
So when will see this monitoring tool in our cars? "The team say the components for the device are readily available and the near-IR technology allows highly accurate readings to be taken and also cuts out interference." The researchers add that "the technology could also potentially be used in roadside congestion charging systems, with less polluting vehicles being charged less."
For more information, this research work has been published in Applied Optics under the name "Multispecies in situ monitoring of a static internal combustion engine by near-infrared diode laser sensors" (Volume 46, Issue 19, Pages 3937-3945). Here is a link to the abstract. "A multispecies near-infrared diode laser spectrometer has been constructed for measurements of carbon monoxide, carbon dioxide, and methane directly in the exhaust of a static internal combustion engine. A wavelength modulation-division multiplexing scheme was implemented for the two distributed feedback diode lasers. Gas concentration variations were observed for changes in operating conditions such as increasing and decreasing the throttle, adjusting the air-fuel ratio, and engine start-up."
Sources: The University of Manchester, August 5, 2007; and various websites
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