Southwest Research Institute® (SwRI®) News
Printer Friendly VersionSwRI to host workshop to"IMPROVE" exhaust emission measurements
San Antonio, Texas -- April 21, 1999 -- Modern limits for vehicle exhaust emissions have become so low that they challenge the precision of traditional laboratory equipment and procedures, according to emission engineers at Southwest Research Institute® (SwRI®) in San Antonio.
To address this issue, SwRI will host a May 11th workshop to discuss ways to modify existing test methods and equipment to improve test repeatability, said Kevin Whitney, senior research engineer in the Department of Emissions Research, part of SwRI's Automotive Products and Emissions Research Division.
During the workshop, SwRI will present plans for an industry consortium called IMPROVE (Investigation of Measurement Precision and Repeatability of Vehicle Emissions) to study the topic in detail.
"Some exhaust emission test procedures specified by the Environmental Protection Agency are more than 20 years old. The equipment used for emission measurements was adequate in the past when exhaust emissions were much higher," said Whitney.
"Now, allowable emissions are lower by orders of magnitude, and the limits of the current test methodologies have been reached."
The newest emission standards, such as the LEV II SULEV standard recently adopted by the State of California, are a factor of 10 lower that those of the early 1990s. This means that exhaust emissions of hydrocarbons and oxides of nitrogen, determined as grams emitted per mile driven, must be measured to three or four decimal places. At such extremely low levels, test-to-test variability limits measurement precision.
The IMPROVE consortium will identify factors that cause test-to-test variability, then investigate methods to reduce variability and improve existing test equipment and techniques. Workshop participants will have ample opportunities to provide suggestions about SwRI's proposed approach and plan for this cooperative research study. When possible, comments will be incorporated into a formal proposal to be issued following the workshop.
For further information, visit the consortium web site at http://www.swri.org/improve or contact Kevin Whitney by phone at (210) 522-5869 or by e-mail at kwhitney@swri.org.
For more information about exhaust emission measurements, contact Joe Fohn, Communications Department, Southwest Research Institute, P.O. Drawer 28510, San Antonio, Texas, 78228-0510, Phone (210) 522-4630, Fax (210) 522-3547.
