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Limitations in the Use of Unipolar Charging for Electrical Mobility Sizing Instruments: A Study of the Fast Mobility Particle Sizer

Levin, M.; Gudmundsson, Anders LU ; Pagels, Joakim LU ; Fierz, M.; Molhave, K.; Löndahl, Jakob LU ; Jensen, K. A. and Koponen, I. K. (2015) In Aerosol Science and Technology 49(8). p.556-565
Abstract
A comparison between three different types of particle sizing instruments (fast mobility particle sizer, FMPS; electrical low pressure impactor, ELPI; and scanning mobility particle sizer, SMPS) and one condensation particle counter (CPC) was made to compare instrument response in terms of size distributions and number concentration. Spherical oil droplets in 39 different sizes, with geometric mean diameter (GMD) ranging from 50nm to 820nm, were used as test particles. Furthermore, a characterization of the FMPS unipolar charger behavior was made to analyze the measured size distributions and number concentrations. The results show that all three sizing-instruments agree well for particle sizes below 200nm, both in terms of size and number... (More)
A comparison between three different types of particle sizing instruments (fast mobility particle sizer, FMPS; electrical low pressure impactor, ELPI; and scanning mobility particle sizer, SMPS) and one condensation particle counter (CPC) was made to compare instrument response in terms of size distributions and number concentration. Spherical oil droplets in 39 different sizes, with geometric mean diameter (GMD) ranging from 50nm to 820nm, were used as test particles. Furthermore, a characterization of the FMPS unipolar charger behavior was made to analyze the measured size distributions and number concentrations. The results show that all three sizing-instruments agree well for particle sizes below 200nm, both in terms of size and number concentration, but the FMPS deviates clearly when particle sizes exceed 200nm. Above this, the FMPS underestimates the particle size throughout the remainder of the size range, with an apparent upper limit for GMD of 300nm. It also estimates a higher particle number concentration as compared to the other instruments. Analysis of the 22 FMPS electrometer currents and calculation of average number of charges per particle show a diameter dependence of response of [GRAPHICS] for the FMPS unipolar charger. The resulting calculated electrical mobility showed a minimum in mobility for spherical particles at 577nm, which indicates an interfering range of particles above the measurement range, but below the cut-off of the inlet pre-separator (1 mu m). The study concludes that particle distributions with a true GMD above 200nm cannot be measured reliably with the FMPS. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Aerosol Science and Technology
volume
49
issue
8
pages
556 - 565
publisher
Taylor & Francis
external identifiers
  • wos:000356322800001
  • scopus:84937807712
ISSN
1521-7388
DOI
10.1080/02786826.2015.1052039
language
English
LU publication?
yes
id
4ba7f18c-aada-41db-bdcf-c1fe4f1c98b3 (old id 7601988)
date added to LUP
2015-07-22 16:05:14
date last changed
2017-10-01 03:21:53
@article{4ba7f18c-aada-41db-bdcf-c1fe4f1c98b3,
  abstract     = {A comparison between three different types of particle sizing instruments (fast mobility particle sizer, FMPS; electrical low pressure impactor, ELPI; and scanning mobility particle sizer, SMPS) and one condensation particle counter (CPC) was made to compare instrument response in terms of size distributions and number concentration. Spherical oil droplets in 39 different sizes, with geometric mean diameter (GMD) ranging from 50nm to 820nm, were used as test particles. Furthermore, a characterization of the FMPS unipolar charger behavior was made to analyze the measured size distributions and number concentrations. The results show that all three sizing-instruments agree well for particle sizes below 200nm, both in terms of size and number concentration, but the FMPS deviates clearly when particle sizes exceed 200nm. Above this, the FMPS underestimates the particle size throughout the remainder of the size range, with an apparent upper limit for GMD of 300nm. It also estimates a higher particle number concentration as compared to the other instruments. Analysis of the 22 FMPS electrometer currents and calculation of average number of charges per particle show a diameter dependence of response of [GRAPHICS] for the FMPS unipolar charger. The resulting calculated electrical mobility showed a minimum in mobility for spherical particles at 577nm, which indicates an interfering range of particles above the measurement range, but below the cut-off of the inlet pre-separator (1 mu m). The study concludes that particle distributions with a true GMD above 200nm cannot be measured reliably with the FMPS.},
  author       = {Levin, M. and Gudmundsson, Anders and Pagels, Joakim and Fierz, M. and Molhave, K. and Löndahl, Jakob and Jensen, K. A. and Koponen, I. K.},
  issn         = {1521-7388},
  language     = {eng},
  number       = {8},
  pages        = {556--565},
  publisher    = {Taylor & Francis},
  series       = {Aerosol Science and Technology},
  title        = {Limitations in the Use of Unipolar Charging for Electrical Mobility Sizing Instruments: A Study of the Fast Mobility Particle Sizer},
  url          = {http://dx.doi.org/10.1080/02786826.2015.1052039},
  volume       = {49},
  year         = {2015},
}