California Air Resources Board

Principal Investigator/Author: Kent Johnson

Contractor: University of California, Riverside

Contract number: 21RD007

Project Status: Active

Relevant CARB programs: Diesel Vehicles, California Greenhouse Gas Emission Inventory Program, Mobile Source Emissions Research Program, Heavy-Duty Low NOx

Topic areas: Climate Change, Air Pollution, On-Road Heavy-Duty Vehicles

Research Summary:

CARB has been developing and implementing a range of different regulatory programs to reduce mobile source emissions. Accurate, stable, and durable on-board sensors are necessary for implementing these programs effectively. The lower emissions levels needed to meet air quality goals necessitate on-board sensors that perform better than current technology is delivering. The objective of this research is to evaluate the potential of using state of the-art and innovative sensor technologies in meeting and enhancing the needs for existing and future regulatory programs. The research will monitor NOX, PM, NH3, and CO2 emissions and vehicle weight from 100 on-road heavy-duty diesel vehicles (HDDVs) and 20 large off-road diesel engines (ORDEs) using state-of-the-art and emerging technology sensors. This research will include both laboratory and field testing to evaluate sensor accuracy, precision, linearity, detection limit, measurement range, cross-species interference, and other metrics. This research will identify the advantages and limitations of on-board sensors for regulatory programs, and the real-world datasets collected from both HDDVs and ORDEs will be used to characterize emissions and activity patterns that can be referenced for emission inventories and current and future regulatory programs.

Keywords: onboard sensors; future onboard sensor technologies; sensor performance; on-/off-road heavy-duty vehicle emission research; nitrogen oxides; ammonia; greenhouse gas emission reduction; particulate matter; activity of on-/off-road heavy-duty vehicles