Measurement of Carbon Monoxide in Auto Exhaust Using a Fast and Inexpensive Sensor


Dan Jaffe and Rick Vos

University of Washington Bothell

Submitted to the Journal of College Science Teaching, 3 May, 2002



Carbon monoxide is an important pollutant because of its severe health effects at high concentrations.  In urban areas, the primary source of CO is vehicle emissions from incomplete combustion.  Previous studies have shown that a small number of high emitting vehicles are responsible for the majority of the CO emissions in most urban areas.  This information can then be used to examine a number of interesting hypotheses with respect to vehicle CO emissions.  Because there are no inexpensive devices available to test the CO output from vehicles, it was necessary for us to develop our own exhaust tester from readily available components.  The exhaust tester we developed costs approximately $450 and can test up to 20 vehicles per hour.  We have used this tester in several undergraduate classes to examine the CO emissions from vehicles arriving onto our campus.  Using the CO data collected, and simultaneous survey data from each driver, the students are able to examine a variety of interesting hypotheses.