title: Measuring Particulate Emissions of Light Duty Passenger Vehicles Using Integrated Particle Size Distribution (IPSD).
abstract: The California Air Resources Board (ARB) adopted the low emission vehicle (LEV) III particulate matter (PM) standards in January 2012, which require, among other limits, vehicles to meet 1 mg/mi over the federal test procedure (FTP). One possible alternative measurement approach evaluated to support the implementation of the LEV III standards is integrated particle size distribution (IPSD), which reports real-time PM mass using size distribution and effective density. The IPSD method was evaluated using TSI's engine exhaust particle sizer (EEPS, 5.6-560 nm) and gravimetric filter data from more than 250 tests and 34 vehicles at ARB's Haagen-Smit Laboratory (HSL). IPSD mass was persistently lower than gravimetric mass by 56-75% over the FTP tests and by 81-84% over the supplemental FTP (US06) tests. Strong covariance between the methods suggests test-to-test variability originates from actual vehicle emission differences rather than measurement accuracy, where IPSD offered no statistical improvement over gravimetric measurement variability.
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: David C
authors.initials: DC
authors.lastname: Quiros
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Sherry
authors.initials: S
authors.lastname: Zhang
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Satya
authors.initials: S
authors.lastname: Sardar
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kamboures
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: David
authors.initials: D
authors.lastname: Eiges
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Mang
authors.initials: M
authors.lastname: Zhang
authors.affiliation: §Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, Riverside, 1084 Columbia Avenue Riverside, California 92507, United States.
authors.forename: Heejung S
authors.initials: HS
authors.lastname: Jung
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Mccarthy
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: M-C Oliver
authors.initials: MC
authors.lastname: Chang
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ayala
authors.affiliation: ∥Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles 650 Charles E. Young Drive South, Los Angeles, California 90095, United States.
authors.forename: Yifang
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.|∥Department of Environmental Health Sciences, Fielding School of Public Health, University of California, Los Angeles 650 Charles E. Young Drive South, Los Angeles, California 90095, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Huai
authors.affiliation: †California Air Resources Board 1001 I Street, Sacramento, California 95814, United States.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Hu
mesh_terms: D002140:California; D005742:Gasoline / Q000032:analysis; D018986:Motor Vehicles; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D005742:Gasoline; D052638:Particulate Matter; D001335:Vehicle Emissions