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Project at a Glance

Project Status: complete

Title: Motor vehicle sampling experiment

Principal Investigator / Author(s): Richards, L Willard

Contractor: Rockwell International

Contract Number: 3-986 & 4-335

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels


In order to determine the changes in air quality along major freeways resulting from the introduction of catalysts or other control devices on automobiles to reduce the emissions of carbon monoxide and hydrocarbons, measurements of the air quality were performed just before catalyst equipped vehicles were introduced. Data were collected for 12 days in August and September 1974 on either side of the San Diego Freeway in Los Angeles just south of Wilshire Boulevard. Measurements included meteorological conditions, trace gas concentrations, aerosol number concentrations and size distributions and two-hour filter samples which were analyzed for a number of elements and species. The data have been edited and collected into a data base of ten-minute, one-hour and two-hour averages. All known limitations in the data are carefully described. Pollutant concentration differences due to the traffic are tabulated, as well as concentration differences divided by the NOx concentration difference. Reduced nitrogen and sulfur species were observed, as well as a volatile sulfur component in the aerosol. A new method of reducing electrical aerosol analyzer data was developed.


For questions regarding this research project, including available data and progress status, contact: Heather Choi at (916) 322-3893

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