title: Quantifying in-use PM measurements for heavy duty diesel vehicles.
abstract: Heavy duty emissions regulations have recently expanded from the laboratory to include in-use requirements. This paradigm shift to in-use testing has forced the development of portable emissions measurement systems (PEMS) for particulate matter (PM). These PM measurements are not trivial for laboratory work, and are even more complex for in-use testing. This study evaluates five PM PEMS in comparison to UCR's mobile reference laboratory under in-use conditions. Three on-highway, heavy-duty trucks were selected to provide PM emissions levels from 0.1 to 0.0003 g/hp-h, with varying compositions of elemental carbon (EC), organic carbon (OC), and sulfate. The on-road driving courses included segments near sea level, at elevations up to 1500 m, and coastal and desert regions. The photoacoustic measurement PEMS performed best for the non-after treatment system (ATS)-equipped engine, where the PM was mostly EC, with a linear regression slope of 0.91 and an R(2) of 0.95. The PEMS did not perform as well for the 2007 modified ATS equipped engines. The best performing PEMS showed a slope of 0.16 for the ATS-equipped engine with predominantly sulfate emissions and 0.89 for the ATS-equipped engine with predominantly OC emissions, with the next best slope at 0.45 for the predominantly OC engine.
authors.affiliation: Center for Environmental Research and Technology (CE-CERT), College of Engineering, University of California, Riverside, California 92521, USA. kjohnson@cert.ucr.edu
authors.forename: Kent C
authors.initials: KC
authors.lastname: Johnson
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Durbin
authors.forename: Heejung
authors.initials: H
authors.lastname: Jung
authors.forename: David R
authors.initials: DR
authors.lastname: Cocker
authors.forename: Dipak
authors.initials: D
authors.lastname: Bishnu
authors.forename: Robert
authors.initials: R
authors.lastname: Giannelli
mesh_terms: D002244:Carbon / Q000032:analysis; D002852:Chromatography, Ion Exchange; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005742:Gasoline; D005843:Geography; D016014:Linear Models; D018986:Motor Vehicles; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D013431:Sulfates / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D005742:Gasoline; D052638:Particulate Matter; D013431:Sulfates; D001335:Vehicle Emissions; D002244:Carbon