Use of Electrostatic Classification Method to Size 0.1 mum SRM Particles. A Feasibility Study.
Use of Electrostatic Classification Method to Size 0.1
mum SRM Particles. A Feasibility Study.
(2876 K)
Kinney, P. D.; Pui, D. Y. H.; Mulholland, G. W.; Bryner,
N. P.
Journal of Research of the National Institute of
Standards and Technology, Vol. 96, No. 2, 147-176,
March/April 1991.
Keywords:
aerosol generators; atomizers; particle size
Abstract:
The use of the electrostatic classification method for
sizing monodisperse 0.1 mum polystyrene latex (PSL)
spheres has been investigated experimentally. The
objective was to determine the feasibility of using
electrostatic classification as a standard method of
particle sizing in the development of a 0.1 mum particle
diameter Standard Reference Material (SRM). The mean
particle diameter was calculated from a measurement of
the mean electrical mobility of the PSL spheres as an
aerosol using an electrostatic classifier. The
performance of the classifier was investigated by
measuring its transfer funciton, conducting a
sensitivity analysis to verify the governing theoretical
relationships, measuring the repeatability of particle
sizing, and sizing NIST SRM 1691, 0.269 mum and NIST SRM
1690, 0.895 mum particles. Investigations of the
aerosol generator's performance focused on the effect of
impurities in the particle-suspending liquid on the
resulting particle diameter. The uncertainty in
particle diameter determined by electrical mobility
measurements is found to be -3.3% to +3.0%. The major
sources of uncertainty include the flow measurement, the
slip correction, and a dependence of particle size on
the aersol flow rate. It was found that the classifier
could be calibrated to indicate the correct size to
within 0.1% for both SRM particle sizes if the defined
classification length is decreased by 1.9%.
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