Research Projects

Project at a Glance

Project Status: active

Title: Development of a portable in-use reference PM measurement system

Principal Investigator / Author(s): Johnson, Kent C.

Contractor: UC Riverside

Contract Number: 10-311

Research Program Area: Emissions Monitoring & Control

Topic Areas: Mobile Sources & Fuels

Research Summary:

The problem addressed by this proposal is that as vehicular PM emissions continue to be reduced, it is increasingly difficult to reliably measure in-use PM emissions. Protocols based on particle number or portable emissions measurement systems (PEMS) have not been satisfactory for gauging PM mass emissions rates. Comparisons of PEMS based PM measurements to gravimetric reference methods reveal significant disparities, with deviations on the order of 100%. This poor correlation does not indicate faulty real-time instruments, but is the result of different instruments using different measurement principles. The objective of this research is to develop and evaluate a new gravimetric-based system designed specifically for in-use conditions including on-highway, marine, and non-road applications. The system will satisfy ARB's need for in use PM measurements that are collected with PEMS and are comparable to the gravimetric federal reference methods. The system provides a tool to monitor in-use on road vehicle emissions of PM which allows for compliance testing, general real-world emission monitoring, and collection of on-road emissions data to supplement emission inventory models. These capabilities are essential to evaluate the effectiveness of the Board's diesel PM emission control policies, and to guide future policy decisions in this realm.


For questions regarding research reports, contact: Heather Choi at (916) 322-3893

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