General Motors Corporation has installed its first production Bag Mini-Diluter Emission Test Site. This site is capable of conducting chassis dynamometer tests in either traditional CFV (Critical Flow Venturi) mode, or BMD (Bag Mini-Diluter) mode, and a combination mode in which both technologies sample simultaneously. This paper discusses ambient interferent (hydrocarbon and humidity) contamination issues which impact data resolution and measurement accuracy as emission standards are lowered. Solutions are recommended which compensate for these effects. This document examines new technologies required for accurate BMD measurements, and presents data obtained from running the site in the dual sampling mode utilizing a four-cylinder PZEV (Partial Zero Emission Vehicle) vehicle. When examined for low variability, data obtained from a PZEV indicated that the BMD was at least equal to the CFV for HC, CH4, NMHC, and CO and better than the CFV for NOx and CO2 by 5 and 3 times respectively. The CFV continues to show that it under-reports HC and NMHC and over-reports CH4 when compared to the BMD by 4 %, 10 %, and 30 % respectively. Based on a SULEV hydrocarbon standard of 0.010 mg/mile, ambient air interferent is effectively 19 times higher than the SULEV standard.
Evaluation of improved bag mini-diluter system for low level emissions measurements
Bewertung eines verbesserten Bag-Mini-Diluter-Systems für Messungen von Niedrigniveauemissionen
2002
17 Seiten, 14 Bilder, 3 Tabellen, 8 Quellen
Aufsatz (Konferenz)
Englisch
Evaluation of Improved Bag Mini-Diluter System for Low Level Emissions Measurements
British Library Conference Proceedings | 2002
|Evaluation of Improved Bag Mini-Diluter System for Low Level Emissions Measurements
SAE Technical Papers | 2002
|Evaluation of improved bag mini-diluter system for low level emissions measurement
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