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Title: Aerosol mobility imaging for rapid size distribution measurements

Abstract

A parallel plate dimensional electrical mobility separator and laminar flow water condensation provide rapid, mobility-based particle sizing at concentrations typical of the remote atmosphere. Particles are separated spatially within the electrical mobility separator, enlarged through water condensation, and imaged onto a CCD array. The mobility separation distributes particles in accordance with their size. The condensation enlarges size-separated particles by water condensation while they are still within the gap of the mobility drift tube. Once enlarged the particles are illuminated by a laser. At a pre-selected frequency, typically 10 Hz, the position of all of the individual particles illuminated by the laser are captured by CCD camera. This instantly records the particle number concentration at each position. Because the position is directly related to the particle size (or mobility), the particle size spectra is derived from the images recorded by the CCD.

Inventors:
; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1264415
Patent Number(s):
9,395,281
Application Number:
14/434,263
Assignee:
BROOKHAVEN SCIENCE ASSOCIATES, LLC (Upton, NY) BNL
DOE Contract Number:
AC02-98CH10886
Resource Type:
Patent
Resource Relation:
Patent File Date: 2013 Oct 08
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 42 ENGINEERING

Citation Formats

Wang, Jian, Hering, Susanne Vera, Spielman, Steven Russel, and Kuang, Chongai. Aerosol mobility imaging for rapid size distribution measurements. United States: N. p., 2016. Web.
Wang, Jian, Hering, Susanne Vera, Spielman, Steven Russel, & Kuang, Chongai. Aerosol mobility imaging for rapid size distribution measurements. United States.
Wang, Jian, Hering, Susanne Vera, Spielman, Steven Russel, and Kuang, Chongai. 2016. "Aerosol mobility imaging for rapid size distribution measurements". United States. doi:. https://www.osti.gov/servlets/purl/1264415.
@article{osti_1264415,
title = {Aerosol mobility imaging for rapid size distribution measurements},
author = {Wang, Jian and Hering, Susanne Vera and Spielman, Steven Russel and Kuang, Chongai},
abstractNote = {A parallel plate dimensional electrical mobility separator and laminar flow water condensation provide rapid, mobility-based particle sizing at concentrations typical of the remote atmosphere. Particles are separated spatially within the electrical mobility separator, enlarged through water condensation, and imaged onto a CCD array. The mobility separation distributes particles in accordance with their size. The condensation enlarges size-separated particles by water condensation while they are still within the gap of the mobility drift tube. Once enlarged the particles are illuminated by a laser. At a pre-selected frequency, typically 10 Hz, the position of all of the individual particles illuminated by the laser are captured by CCD camera. This instantly records the particle number concentration at each position. Because the position is directly related to the particle size (or mobility), the particle size spectra is derived from the images recorded by the CCD.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2016,
month = 7
}

Patent:

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  • This study discusses, a fast integrated mobility spectrometer (FIMS) was previously developed to characterize submicron aerosol size distributions at a frequency of 1 Hz and with high size resolution and counting statistics. However, the dynamic size range of the FIMS was limited to one decade in particle electrical mobility. It was proposed that the FIMS dynamic size range can be greatly increased by using a spatially varying electric field. This electric field creates regions with drastically different field strengths in the separator, such that particles of a wide diameter range can be simultaneously classified and subsequently measured. A FIMS incorporatingmore » this spatially varying electric field is developed. This paper describes the theoretical frame work and numerical simulations of the FIMS with extended dynamic size range, including the spatially varying electric field, particle trajectories, activation of separated particles in the condenser, and the transfer function, transmission efficiency, and mobility resolution. The influences of the particle Brownian motion on FIMS transfer function and mobility resolution are examined. The simulation results indicate that the FIMS incorporating the spatially varying electric field is capable of measuring aerosol size distribution from 8 to 600 nm with high time resolution. As a result, the experimental characterization of the FIMS is presented in an accompanying paper.« less
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