This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A New Proportional Collection System for Extremely Low Emission Measurement in Vehicle Exhaust
ISSN: 0148-7191, e-ISSN: 2688-3627
Published May 03, 1999 by SAE International in United States
Annotation ability available
A new proportional collection system for extremely low tailpipe emission measurement in transient conditions has been developed. The new system can continuously sample a minute flow of exhaust gas, at a rate that is proportional to the engine exhaust rate. A zero grade gas dilution technique is utilized to prevent the influence of pollutants in atmospheric air that are the same concentration level as those in the exhaust gas. The system has accuracy within ±5%.
For the direct exhaust gas flow meter, a pitot tube type flow meter is utilized as it is simple, heat resistant, sufficiently accurate and has low flow-resistance characteristic. For the collection and dilution controllers, two mass flow controllers (MFC) were adopted. The MFCs' output can be adversely influenced by variation of the specific heat of the sample gas, resulting in flow reporting error. To correct this error a new corrective apparatus, which is able to sense variation of specific heat of the sample gas, was added to the new system. To compensate for collection errors that were caused by “ramp-up” time delay of the MFC, it was necessary to set the gas and signal relative delay correctly. Additionally, a new delay adjustment method enabled the system to be optimized for proper transient time-alignment, thus resulting in good overall system performance.
CitationYoda, K. and Uchida, K., "A New Proportional Collection System for Extremely Low Emission Measurement in Vehicle Exhaust," SAE Technical Paper 1999-01-1460, 1999, https://doi.org/10.4271/1999-01-1460.
- California Air Resources Board CARB Proposed Amendments to California's Low-Emission Vehicle Regulations “LEV II” Draft Preliminary Report November 1997 El Monte, CA, USA
- Code of Federal Regulations, Parts 86; Title 40-Protection of Environment Office of the Federal Register, National Archives and Records Administration Washington, D.C. 1997
- McLeod Jon Nagy Don Schroeder Pat Thiel Sue Dearth Mark A. Colvin Alex D. Webb Tim Carduner Keith R. Schuetzle Dennis Middleton Rick Schlenker Ann M. “A Sampling System for the Measurement of PreCatalyst Emissions from Vehicles Operating Under Transient Conditions.” SAE 930141 1993
- Beck Martin Hinterhofer Konrad “Direct High Dynamic Flow Measurement in the Exhaust of Combustion Engines.” SAE 980880 1998