Diesel Exhaust/Mine Dust Virtual Impactor Personal Aerosol Sampler: Design, Calibration and Field Evaluation

Marple, Virgil A.; Rubow, Kenneth L.; Olson, Bernard A.

doi:10.1080/02786829408959735

Cited by 16 publications

(6 citation statements)

References 11 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9 There is a growing need for both a detailed size classification and chemical characterization of the personal exposure to PM. Various personal monitoring systems have been developed [10][11][12] to measure some size fractions of PM (i.e., PM 2.5 and PM 10 ), as well as chemical components such as some inorganic species (e.g., sulfates, nitrates) and elemental and organic carbon.…”

Section: Introductionmentioning

confidence: 99%

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Demokritou

Gupta

Ferguson

et al. 2002

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

This paper presents the design and laboratory evaluation of a personal cascade impactor. The system is compact, lightweight, and uses a single battery-operated sampling pump. It operates at a flow rate of 5 L/min and consists of four impaction stages, each equipped with slit-shaped acceleration nozzles, and a backup filter. The impactor was calibrated using polydisperse particles. The 50% cut points of the four stages were 9.6, 2.6, 1.0, and 0.5 microm, respectively. The backup filter is placed downstream of the fourth stage and is used to collect the particles with an aerodynamic diameter smaller than 0.5 microm (dp < 0.5 microm). The major feature of this novel sampler is its ability not only to fractionate the particles with an aerodynamic diameter smaller than 10 microm to the various size fractions, but also to collect them onto relatively small polyurethane foam substrates without using adhesives. Although the impaction substrates are not coated with adhesives such as grease or mineral oil, particle bounce and re-entrainment losses were found to be insignificant. Interstage losses of particles smaller than 0.5 microm were less than 10%; for fine particles, less than 5%; and for coarse particles, less than 12%. The pressure drop across the four stages and the backup filter were 0.015 kPa (0.153 cm H2O),0.025 kPa (0.255 cm H2O), 0.274 kPa (2.794 cm H2O), 0.323 kPa (3.294 cm H2O), and 0.370 kPa (3.773 cm H2O), respectively. Particles can be easily recovered from the foam substrates using aqueous extraction.

show abstract

Section: Introductionmentioning

confidence: 99%

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Demokritou

Gupta

Ferguson

et al. 2002

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

show abstract

“…The 50% cutpoint of the impactor was calculated from the corresponding St value of 0.47. This value has been used by Marple et al (1995) for a minor-to-total flow ratio of 0.1 based on numerical simulations and experimental studies. It should be noted that a more precise determination (i.e., an experimental verification) of the cutpoint in our system was not considered essential to our studies.…”

Section: Ultrafine Particlesmentioning

confidence: 99%

Inertial Separation of Ultrafine Particles Using a Condensational Growth/Virtual Impaction System

Sioutas

Koutrakis

1996

Aerosol Science and Technology

View full text Add to dashboard Cite

ABSTRACT. A system for the separation of ultrafine particles (i.e., particles smaller than 0.1 pm) has been developed and evaluated. Ultrafine particles are first grown by means of supersaturation to a size that can be easily separated in a virtual impactor. Thus, inertial separation of ultrafine particles occurs without subjecting them to a high vacuum. The condensational growthlvirtual impaction system has been evaluated using monodisperse 0.05 and 0.1 p m fluorescent PSL particles, as well as polydisperse ultrafine ammonium sulfate and potassium nitrate aerosols. The generated aerosols were first drawn over a pool of warm water (50°C) where they became saturated. Subsequently, the saturated aerosol was drawn through a cooling tube (8°C) where particles grew due to supersaturation to sizes in the range 1 . 0 4 0 pm. By placing a virtual impactor with a theoretical 50% cutpoint of 1.4 p m downstream of the condenser, ultrafine particles were separated from the majority (i.e., 90%) of the surrounding gas. The sampling flow rate of the virtual impactor was 8 Llmin and its minor-to-total flow ratio was 0.1. For these operating conditions, the particle collection efficiency of the virtual impactor averaged to about 0.9 for particle concentrations in the range 7 X lo4-5 X 10' particles/cm3. Particle losses through the system were found less than 5%. Increasing the particle concentration to levels in the range lo6-10' particles/cm3 resulted in a decrease in the collection efficiency of the virtual impactor to about 50-70%, presumably due to the smaller final droplet size to which the ultrafine particles grew for the available supersaturation.

show abstract

“…33,39 The accuracy, precision, and sensitivity of the PEM samplers have been well characterized. 26,28,[56][57][58][59] Hourly PM 2.5 concentrations measured using the DustTrak were averaged over 12-hr periods and were compared to the 12-hr integrated PM 2.5 PEM measurements. The total number of PEM-DustTrak pairs was 35 in the summer and 42 in the winter.…”

Section: Ambient Validation Tests For Dusttrak Aerosol Monitormentioning

confidence: 99%

Laboratory and Field Evaluation of Measurement Methods for One-Hour Exposures to O₃, PM₂₅, and CO

Chang¹,

Suh²,

Wolfson³

et al. 2001

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

While researchers have linked acute (less than 12-hr) ambient O 3 , PM 2.5 , and CO concentrations to a variety of adverse health effects, few studies have characterized short-term exposures to these air pollutants, in part due to the lack of sensitive, accurate, and precise sampling technologies. In this paper, we present results from the laboratory and field evaluation of several new (or modified) samplers used in the "roll-around" system (RAS), which was developed to measure 1-hr O 3 , PM 2.5 , and CO exposures simultaneously. All the field evaluation data were collected during two sampling seasons: the summer of 1998 and the winter of 1999.To measure 1-hr O 3 exposures, a new active O 3 sampler was developed that uses two nitrite-coated filters to measure O 3 concentrations. Laboratory chamber tests found that the active O 3 sampler performed extremely well, with a collection efficiency of 0.96 that did not vary with temperature or relative humidity (RH). In field collocation comparisons with a reference UV photometric monitor, the active O 3 sampler had an effective collection efficiency ranging between 0.92 and 0.96 and a precision for 1-hr measurements ranging between 4 and 6 parts per billion (ppb). The limits of detection (LOD) of this method were 9 ppb-hr for the chamber tests and ~16 ppb-hr for the field comparison tests. PM 2.5 and CO concentrations were measured using modified continuous monitors-the DustTrak and the Langan, respectively. A size-selective inlet and a Nafion dryer were placed upstream of the DustTrak inlet to remove particles with aerodynamic diameters greater than 2.5 µm and to dry particles prior to the measurements, respectively. During the field validation tests, the DustTrak consistently reported higher PM 2.5 concentrations than those obtained by the collocated 12-hr PM 2.5 PEM samples, by approximately a factor of 2. After the DustTrak response was corrected (correction factor of 2.07 in the summer and 2.02 in the winter), measurements obtained using these methods agreed well with R 2 values of 0.87 in the summer and 0.81 in the winter. The results showed that the DustTrak can be used along with integrated measurements to measure the temporal and spatial variation in PM 2.5 exposures. Finally, during the field validation tests, CO concentrations measured using the Langan were strongly correlated with those obtained using the reference method when the CO levels were above the LOD of the instrument [~1 part per million (ppm)].

show abstract

Diesel Exhaust/Mine Dust Virtual Impactor Personal Aerosol Sampler: Design, Calibration and Field Evaluation

Cited by 16 publications

References 11 publications

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Inertial Separation of Ultrafine Particles Using a Condensational Growth/Virtual Impaction System

Laboratory and Field Evaluation of Measurement Methods for One-Hour Exposures to O₃, PM₂₅, and CO

Contact Info

Product

Resources

About

Diesel Exhaust/Mine Dust Virtual Impactor Personal Aerosol Sampler: Design, Calibration and Field Evaluation

Cited by 16 publications

References 11 publications

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Development and Laboratory Performance Evaluation of a Personal Cascade Impactor

Inertial Separation of Ultrafine Particles Using a Condensational Growth/Virtual Impaction System

Laboratory and Field Evaluation of Measurement Methods for One-Hour Exposures to O3, PM25, and CO

Contact Info

Product

Resources

About

Laboratory and Field Evaluation of Measurement Methods for One-Hour Exposures to O₃, PM₂₅, and CO