Comparison of Exhaust Particle Number Measured by EEPS, CPC, and ELPI

Zervas, Efthimios; Dorlhène, Pascal

doi:10.1080/02786820600844093

Cited by 55 publications

(35 citation statements)

References 14 publications

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“…Based on reference SMPS measurements, the distribution is a unimodal with a GMD of 52 nm. This GMD is consistent with previous studies (Harris and Maricq 2001;Zervas and Dorlhene 2006) and suggests that the majority of the particles are accumulation mode soot particles with a mass-mobility scaling exponent of approximately 2.2 (Mariq and Xu 2004; Olfert et al 2007). We expect this condition to represent the relative performance of the size distribution methods when measuring diesel exhaust from engines operating on ULSD without DPF aftertreatment.…”

Section: Resultssupporting

confidence: 81%

“…Early developments by Mirme (1994) at Tartu University and Biskos et al (2005), led to the commercialized systems available today, such as the EEPS by TSI and the DMS500 by Cambustion. In recent years, both the EEPS and DMS500 have been widely used for emission measurement and characterization (Liu et al 2005;Rubino et al 2005;Yao et al 2006;Zervas and Dorlhene, 2006;Zheng et al 2012). The two instruments have multiple electrometers downstream of a corona charger to measure size distributions.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of Vehicle Exhaust Particle Size Distributions Measured by SMPS and EEPS During Steady-State Conditions

Xue

Wang

et al. 2015

Aerosol Science and Technology

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Fast-sizing spectrometers, such as the TSI Engine Exhaust Particle Sizer (EEPS), have been widely used to measure transient particle size distributions of vehicle exhaust. Recently, size distributions measured during different test cycles have begun to be used for calculating suspended particulate mass; however, several recent evaluations have shown some deficiencies in this approach and discrepancies relative to the gravimetric reference method. The EEPS converts electrical charge carried by particles into size distributions based on mobility classification and a specific calibration, and TSI recently released a matrix optimized for vehicle emissions as described by Wang et al. (Submitteda). This study evaluates the performance of the new matrix (soot matrix) relative to the original matrix (default matrix) and reference size distributions measured by a scanning mobility particle sizer (SMPS). Steady-state particle size distributions were generated from the following five sources to evaluate exhaust particulates with various morphologies estimated by mass-mobility scaling exponent: (1) A diesel generator operating on ultralow sulfur diesel, (2) a diesel generator operating on biodiesel, (3) a gasoline direct-injection vehicle operating at two speeds, (4) a conventional port-fuel injection gasoline vehicle, and (4) a light-duty diesel (LDD) vehicle equipped with a diesel particulate filter. Generally, the new soot matrix achieved much better agreement with the SMPS reference for particles smaller than 30 nm and larger than 100 nm, and also broadened the accumulation mode distribution that was previously too narrow using the default matrix. However, EEPS distributions still did not agree with SMPS reference measurements when challenged by a strong nucleation mode during high-load operation of the LDD vehicle. This work quantifies the range of accuracy that can be expected when measuring particle size distribution, number concentration, and integrated particle mass of vehicle emissions when using the new static calibration derived based on the properties of classical diesel soot.

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Section: Resultssupporting

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Comparison of Vehicle Exhaust Particle Size Distributions Measured by SMPS and EEPS During Steady-State Conditions

Xue

Wang

et al. 2015

Aerosol Science and Technology

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“…The 11-to 13-stage Andersen Low Pressure Impactor (ALPI; Yamasaki et al, 2000;Pagels et al, 2005;Vaaraslahti et al, 2005;Zervas and Dorlhene, 2006) has multiple jet impaction plates, similar to the BLPI. These are individually manufactured and calibrated.…”

Section: Impactorsmentioning

confidence: 99%

Review of Measurement Methods and Compositions for Ultrafine Particles

Chow

Watson

2007

Aerosol Air Qual. Res.

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Impactor, virtual impactor/aerosol concentrator, and aerodynamic lenses are used to separate the ultrafine particle (UP) fraction from other particle sizes for chemical analysis. Cascade impactors, such as the Micro-Orifice Uniform Deposit Impactor (MOUDI), are most commonly used in field studies, with sampling onto substrates amenable to different chemical analyses.Impactors need sufficient sampling flow rates and homogeneous deposits on the impaction surfaces for multiple chemical analyses. Mass, elements, ions, and carbon fractions can be measured on these substrates by several analytical methods. Specific organic compounds measured by solvent extraction require substantial mass loadings that can only be obtained by compositing samples from several measurement periods unless aerosol concentrators or highvolume sampling devices are used. Thermal desorption-gas chromatographic/mass spectrometry has potential to obtain organic speciation with small sample sizes. Studies of UP composition began in the late 1990s, with 25 ambient studies surveyed here. These are mostly from urban areas. Organic material, including polycyclic aromatic hydrocarbons (PAHs), usually constituted the most abundant portion of UP, with high elemental concentrations found near industrial sites.Much of the UP < 50 nm appears to be semi-volatile, consistent with it being composed by organic materials such as hopanes from engine oils or condensed secondary organic aerosol such as organic acids.

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“…239 A water-based condensation particle counter (CPC; Models 3785 and 3786, TSI, Inc.) 240 -242 has shown similar performance to conventional butanol based-CPCs 243 while avoiding the use of a toxic organic solvent. Fastresponse instruments (e.g., the Engine Exhaust Particle Sizer [EEPS; 10 Hz], the Fast Mobility Particle Sizer [FMPS; 1 sec]) 244,245 have been used for source testing of exhaust emissions. Mohr et al 246 show that fast-response particle measurement methods are feasible for detecting low vehicle emissions with better precision and lower MDLs than gravimetric analysis of integrated samples.…”

Section: Particle Sizingmentioning

confidence: 99%

Advances in Integrated and Continuous Measurements for Particle Mass and Chemical Composition

Chow

Doraiswamy

Watson

et al. 2008

Journal of the Air & Waste Management Association

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Recent improvements in integrated and continuous PM 2.5 mass and chemical measurements from the Supersite program and related studies in the past decade are summarized. Analytical capabilities of the measurement methods, including accuracy, precision, interferences, minimum detectable levels, comparability, and data completeness are documented. Upstream denuders followed by filter packs in integrated samplers allow an estimation of sampling artifacts. Efforts are needed to: (1) address positive and negative artifacts for organic carbon (OC), and (2) develop carbon standards to better separate organic versus elemental carbon (EC) under different temperature settings and analysis atmospheres. Advances in thermal desorption followed by gas chromatography/ mass spectrometry (GC/MS) provide organic speciation of approximately 130 nonpolar compounds (e.g., n-alkanes, alkenes, hopanes, steranes, and polycyclic aromatic hydrocarbons [PAHs]) using small portions of filters from existing integrated samples. Speciation of water-soluble OC (WSOC) using ion chromatography (IC)-based instruments can replace labor-intensive solvent extraction for many compounds used as source markers. Thermal gasbased continuous nitrate and sulfate measurements underestimate filter ions by 10 -50% and require calibration against on-site filter-based measurements. IC-based instruments provide multiple ions and report comparable (Ϯ10%) results to filter-based measurements. Maintaining a greater than 80% data capture rate in continuous instruments is labor intensive and requires experienced operators. Several instruments quantify black carbon (BC) by optical or photoacoustic methods, or EC by thermal methods. A few instruments provide real-time OC, EC, and organic speciation. BC and EC concentrations from continuous instruments are highly correlated but the concentrations differ by a factor of two or more. Site-and season-specific mass absorption efficiencies are needed to convert light absorption to BC. Particle mass spectrometers, although semiquantitative, provide much information on particle size and composition related to formation, growth, and characteristics over short averaging times. Efforts are made to quantify mass by collocating with other particle sizing instruments. Common parameters should be identified and consistent approaches are needed to establish comparability among measurements.

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Comparison of Exhaust Particle Number Measured by EEPS, CPC, and ELPI

Cited by 55 publications

References 14 publications

Comparison of Vehicle Exhaust Particle Size Distributions Measured by SMPS and EEPS During Steady-State Conditions

Comparison of Vehicle Exhaust Particle Size Distributions Measured by SMPS and EEPS During Steady-State Conditions

Review of Measurement Methods and Compositions for Ultrafine Particles

Advances in Integrated and Continuous Measurements for Particle Mass and Chemical Composition

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