The hypothesis of this thesis is that the time-of-flight method of determining an estimate of the aerodynamic diameter of aerosol particles is fundamentally flawed when applied to non-spherical and/or non-unit density particles. Such a particle-sizing system, the TSI Aerodynamic Particle Sizer, is challenged with solid, non-spherical particles of known aerodynamic diameter to assess the influence of particle shape on instrument response. The aerodynamic diameter of the non-spherical particles is also determined under gravitational settling. Deposits that had been size-separated are resuspended for aerodynamic sizing by the APS. The experimental study is supplemented by a theoretical investigation of the relative effects of particle density and shape on APS-measured diameters. This is achieved through the development of a computational routine to calculate the trajectories of particles of various densities and shapes through the APS nozzle and sensing zone. The results of these calculations are compared with the experimentally-measured APS performance. The consequences for the traceability and accuracy of data measured using this technique are assessed in the light of the outcome of both aspects of the study.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:362758 |
Date | January 1996 |
Creators | Marshall, I. M. |
Publisher | Loughborough University |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | https://dspace.lboro.ac.uk/2134/14469 |
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