Evaluation of a cost-effective roadside sensor platform for identifying high emitters

Area of Science:

• Environmental Science
• Engineering
• Atmospheric Chemistry

Background:

• High-emission vehicles significantly contribute to air pollution through elevated nitrogen oxide (NO) and particle number (PN) emissions.
• Efficient and cost-effective instruments are crucial for identifying these high emitters in real-world traffic conditions.

Purpose of the Study:

• To develop and evaluate a compact, cost-effective sensor platform for identifying high-emission vehicles.
• To measure key pollutants and derive emission factors from vehicle exhaust plumes.

Main Methods:

• A novel sensor platform was deployed roadside to measure carbon dioxide, PN, and NO concentrations in diesel truck exhaust plumes.
• Plume-based emission factors were calculated, and results were compared with a benchmark portable emission measurement system.
• The influence of aftertreatment systems and driving conditions on emission factors was analyzed.

Main Results:

• The sensor platform successfully measured CO2, PN, and NO, enabling the derivation of plume-based emission factors.
• Three diesel trucks with malfunctioning aftertreatment systems were identified as potential high emitters based on NO and PN emission factors.
• NO emission factors correlated well with a benchmark system, and the platform highlighted the impact of aftertreatment and driving conditions.

Conclusions:

• The developed sensor platform demonstrates feasibility for identifying high-emission vehicles.
• Its cost-effective and compact design supports networked deployment for roadside screening.
• This technology can effectively support regulatory protocols for managing vehicle emissions.