Technical Paper
Emissions Correlation Between a Partial-Flow Diluter and The Full-Flow Constant Volume Sampler (CVS) for a Heavy-Duty Vehicle Under Steady-State Operation
2005-10-24
2005-01-3798
The California Air Resources Board (CARB) examined the performance of a Partial Flow Sampling System (PFSS) against a reference Constant Volume Sampling (CVS) system in measuring emissions from a heavy-duty vehicle (HDV) during dynamometer testing at CARB's Stockton Heavy-Duty Emissions Laboratory (SL). The SL PFSS system is a Sierra BG-2 system that uses flow-based (rather than CO2-based) dilution. The CVS system uses the University of California, Riverside's (UCR) Mobile Emissions Laboratory (MEL). The test vehicle was a 2000 model-year HD tractor powered by a CAT C-15 engine. Exhaust samples were collected simultaneously with the SL and MEL systems and analyzed for total particulate matter (PM), oxides of nitrogen (NOx), carbon dioxide (CO2), carbon monoxide (CO), and total hydrocarbons (THC). The samples were taken during steady-state vehicle operation. Each test mode was repeated seven times in each of two patterns: consecutive and sequential.
