This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Uncertainties in Measurements of Emissions in Chassis Dynamometer Tests
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 01, 2014 by SAE International in United States
Annotation ability available
This paper illustrates a method to determine the experimental uncertainties in the measurement of tailpipe emissions of carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, and particulates of medium-, and heavy-duty vehicles when tested on a heavy-duty chassis dynamometer and full-scale dilution tunnel. Tests are performed for different chassis dynamometer driving cycles intended to simulate a wide range of operating conditions. Vehicle exhaust is diluted in the dilution tunnel by mixing with conditioned air. Samples are drawn through probes for raw exhaust, diluted exhaust and particulates and measured using laboratory grade emission analyzers and a microbalance. At the end of a driving cycle, results are reported for the above emissions in grams/mile for raw continuous, dilute continuous, dilute bag, and particulate measurements. An analytical method is developed in the present study to estimate the measurement uncertainties in emissions for a test cycle, due to the buildup of measurement uncertainties as they propagate through the system. The linearity, repeatability and noise of the measuring instruments of the system, as specified in instrument's manuals are used in the calculations. It is found that measurement uncertainties are lower for raw continuous measurements, and higher for dilute bag measurements. Analysis shows that uncertainty in concentration measurement is the major component of total uncertainty, and that uncertainty is a function of the duration of the test and the ratio of measured value to full scale range of the instrument. A computer generated Monte Carlo simulation is used to validate the present analysis. Data from one steady state propane injection test and a transient driving cycle are used to compare results from our analysis and Monte Carlo simulation. It is found that the Monte Carlo simulation shows good agreement with the results from the uncertainty analysis. Uncertainties in emissions measurement from three dynamometer- based tests are discussed. A list of abbreviations used is given at the end of the paper.
CitationMohanta, L., Iyer, S., Mishra, P., and Klinikowski, D., "Uncertainties in Measurements of Emissions in Chassis Dynamometer Tests," SAE Technical Paper 2014-01-1584, 2014, https://doi.org/10.4271/2014-01-1584.
- Health Effects Institute 2009 Traffic-related Air Pollution: a Critical Review of the Literature on Emissions, Exposure, and Health Effects (Boston, MA: Health Effects Institute, Special Report 17)
- Durbin T D, Wilson RD, Norbeck J M, Miller J W, Huai T and Rhee S H 2002 Estimates of the emission rates of ammonia from light-duty vehicles using standard chassis dynamometer test cycles Atmospheric Environment 36 1475
- Beddows D C S and Harrison R M 2008 Comparison of average particle number emission factors for heavy and light duty vehicles derived from rolling chassis dynamometer and field studies Atmospheric Environment 42 7954
- Hesterberg T, Lapin C and Bunn WB 2008 A Comparison of Emissions from Vehicles Fueled with Diesel or Compressed Natural Gas Environmental Science & Technology 42 6437
- Chen C, Huang C, Jing Q, Wang H, Pan H, Li L, Zhao J, Dai Y, Huang H, Schipper L and Streets D G 2007 On-road emission characteristics of heavy-duty diesel vehicles in Shanghai Atmospheric Environment 41 5334
- Huang X, Clark N N, Thompson G J, Gautam M, Carder D and Strimer C 2006 Production of NOX from tractor-trailor operation Proc. Int. Symp. On Heavy Vehicle Weights and Dimensions (State College: Pennsylvania) session 2.
- Fontaras G, Martini G, Manfredi U, Marotta A, Krasenbrink A, Maffioletti F, Terenghi R and Colombo M 2012 Assessment of on-road emissions of four Euro V diesel and CNG waste collection trucks for supporting air-quality improvement initiatives in the city of Milan. Science of the Total Environment 426 65-72
- Pelkmans L and Debal P 2006 Comparison of on-road emissions with emissions measured on chassis dynamometer test cycles Transportation Research Part D 11 233
- Moffat R J 1988 Describing the Uncertainties in experimental measurement methods Experimental Thermal and Fluid Science 1 283
- RTI International 2007 Emission Factor Uncertainty assessment (Research Triangle Park, NC)
- de Melo, T. and Dias, A., “Experimental Methods for Reducing Uncertainty of Measurement on Vehicle Emission Testing,” SAE Technical Paper 2004-01-1961, 2004, doi:10.4271/2004-01-1961.
- Taylor J L 1990 Computer Based Data Acquisition Systems: Design Techniques (Research Triangle Park, NC: Instrument Society of America) p 17-21, 24-25, 72-78
- Taylor J R 1997 An Introduction to Error Analysis (Sausalito, CA: University Science Books) p 45-78, 150
- Coleman H W and Steele J W 1999 Experimentation and uncertainty analysis for engineers (Hoboken, NJ: Wiley Interscience) p 235-242
- You Y J and Owen M 2002 Uncertainties in transient heat transfer measurements International Journal of Heat and Fluid Flow 23 29
- Vardoulakis S, Fisher B E A, Flesca N G and Pericleous K 2002 Model sensitivity and uncertainty analysis using roadside air quality measurements Atmospheric Environment 36 2121