German scientists develop smart way to investigate vehicle emissions - Polidicks

[QUOTE]The Volkswagen scandal underlined the inadequacy of standard lab tests which do not reflect the exhausts produced when driving in the real world. But the University of Heidelberg team is now getting more reliable data by following behind city cars and buses to "sniff" their tailpipe gases. ... "It's very simple. We've got a small instrument on the back seat of our car. We just suck in the air at the front of our car, taking in this plume from the vehicle in front, and get some values." GPS tracks the location. A camera identifies the type of vehicle - motorcycle, car, lorry or bus - and the manufacturer. The team is particularly interested in oxides of nitrogen, which are produced in the combustion process and can be a serious health hazard. ... The group would often come across high-polluting vehicles that had been built to comply with the very latest emissions standards (and before you ask: these were not all VWs). ... Typically, many of the worst offenders were buses, in particular some older models. Bizarrely, one of the buses in Mainz producing very high concentrations of nitrogen dioxide was emblazoned with a campaign urging people to get onboard in order to lower emissions. One clear message, however, does seem to come out of the research: a relatively small number of vehicles on the road is responsible for a high fraction of total emissions. In the case of Mainz, the plumes of 7.6% of vehicles contained more than 500 parts per billion by volume (about 1,000 microgram per cubic metre) of nitrogen dioxide (NO2). But if you could somehow take just these vehicles off the road, you would reduce emissions by 45%. [/QUOTE] [URL="http://www.bbc.co.uk/news/science-environment-36088598"]Source[/URL]

Wouldn't the plume coming from the exhaust become diluted with the surrounding air, thus throwing off NO2 readings? Or could they extrapolate the concentration at a distance? Unless the chase/investigation car was literally bumper to bumper with the suspect vehicle. [QUOTE]In the case of Mainz, the plumes of 7.6% of vehicles contained more than 500 parts per billion by volume (about 1,000 microgram per cubic metre) of nitrogen dioxide (NO2). But if you could somehow take just these vehicles off the road, you would reduce emissions by 45%.[/QUOTE] Holy shit.

[QUOTE=LoneWolf_Recon;50167613]Wouldn't the plume coming from the exhaust become diluted with the surrounding air, thus throwing off NO2 readings? Or could they extrapolate the concentration at a distance? Unless the chase/investigation car was literally bumper to bumper with the suspect vehicle. Holy shit.[/QUOTE] Looks like they are right up their bumper from the picture in the article: [IMG]http://ichef.bbci.co.uk/news/624/cpsprodpb/AFD4/production/_89321054_system.jpg[/IMG] [editline]20th April 2016[/editline] Electric busses need to become more commonplace.

Germans... Constantly striving to overcomplicate things... What are they going to do then drive around as the nitrogen police fining people who have bad cars

[QUOTE=Sableye;50167662]Germans... Constantly striving to overcomplicate things... What are they going to do then drive around as the nitrogen police fining people who have bad cars[/QUOTE] It just provides interesting real world data, and does it in a fairly cheap way.

[QUOTE=Morgen;50167708]It just provides interesting real world data, and does it in a fairly cheap way.[/QUOTE] And might just catch other manufacturers that might do the same shit Volkswagen did.

[QUOTE=Electrocuter;50167776]And might just catch other manufacturers that might do the same shit Volkswagen did.[/QUOTE] Yeah maybe. Nitrogen dioxide is one of the worst emissions from cars as well for people's health.

I have always wondered why we stopped probing the actual tailpipe emissions in the mid 90s. OBD-II does not guarantee the actual exhaust is clean, it's actually rather easy to cheat it. Hotrodders have been doing so since it started, continue to, it's only a surprise we caught a full-on company doing it now. Off the top of me head, if I were to do so, I could just build an Arduino dummy box hooked to the OBD-II port that always fed the computer clean and happy thoughts regardless of what the engine was doing. With that cheater box in my dashboard I could fit a straight-from-the-factory-in-1933 Flathead V8 in my P71 'Vic and the testers would never know it's spewing 1930s era emissions. Incidentally, it's exceedingly difficult to cheat the probe stuffed up the tailpipe. Even with catalytic converters they'd pick up real quick on the theoretical swap above. I say we get rid of this 'plug into the computer' testing we're doing with OBD-II cars. Just probe their ass like we do OBD-I and carburetted vehicles. You can't cheat the probe.

[QUOTE=TestECull;50167860]I say we get rid of this 'plug into the computer' testing we're doing with OBD-II cars. Just probe their ass like we do OBD-I and carburetted vehicles. You can't cheat the probe.[/QUOTE] I'm pretty sure the selected VW cars was cheating probes. The cars detected when they were on a dyno/tester and adjusted to comply with the requirements.

[QUOTE=Sableye;50167662]Germans... Constantly striving to overcomplicate things... What are they going to do then drive around as the nitrogen police fining people who have bad cars[/QUOTE] What's your grudge

[QUOTE=AGMadsAG;50167931]I'm pretty sure the selected VW cars was cheating probes. The cars detected when they were on a dyno/tester and adjusted to comply with the requirements.[/QUOTE] Exactly, the ECU's recognized its current load patterns for if it was being emissions tested in a laboratory setting, so it went into "cheating clean" mode. I'm still surprised they couldn't make the measuring equipment smaller, so they could put it [B]IN[/B] the trunk of the car being tested, and route a hose down to the tailpipe to "sample" the exhaust. Then the researcher would only have to cheat the "trunk open" button, and then drive the car like it was normal commuting. Sure it would distort aerodynamics a bit, but it'll still have less impact than driving with a roofbox on, and it should only be used to verify that the laboratory tests they normally do weren't falsified.