About RapidScreen
How It Works
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Illustration
RapidScreen testing vans set up at highway on-ramps
and other locations where vehicles are accelerating or driving uphill
at a moderate speed, because these conditions generate the most
representative sample of a vehicle’s exhaust emissions.
As a vehicle passes by, the roadside testing equipment
is able to analyze the vehicle’s exhaust in less than a second.
Here’s how RapidScreen works:
1) The vehicle first passes through speed and acceleration
detectors, while an image of the license plate is recorded for identification.
2) The vehicle then passes through the infrared and
ultraviolet beams of the emissions analyzer. A laser light source
directs the beams across the road, where they are bounced off mirrors
and directed back to a detector module. As the light beams are broken
by the vehicle’s exhaust plume, the detector module measures
the levels of carbon monoxide, carbon dioxide, hydrocarbons and
oxides of nitrogen in the plume.
To ensure accurate, uncontaminated readings, RapidScreen
testing vans do not operate during rain, snow, high winds or other
adverse weather conditions. RapidScreen also holds to stricter emissions
limits than those of a standard tailpipe emissions test.
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