AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Intercomparison of Particle Sizing Between AMS, SMPS and FMPS
BERTO LEE, Yong J. Li, Chak K. Chan, Hong Kong University of Science and Technology
Abstract Number: 204 Working Group: Instrumentation and Methods
Abstract Among the most commonly used particle sizing instruments are the Scanning Mobility Particle Sizer (SMPS), a combination of a Differential Mobility Analyzer (DMA) and a Condensation Particle Counter, and more recently the Fast Mobility Particle Sizer (FMPS). Instrumental comparison studies (Jeong et. al, 2009 and Asbach et. al, 2009) of both instruments have so far focused on the comparability of the particle number concentrations and have found significant counting discrepancies. From a comparison of field data acquired at a suburban site in Hong Kong during springtime 2011, a significant sizing discrepancy between the species mass size distribution from a High-Resolution Time-Of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and the volume size distribution from a collocated Fast Mobility Particle Sizer (FMPS) was observed. Subsequent experimental sizing verifications with various polydisperse inorganic aerosol and PSL particle solutions employing the HR-ToF-AMS, FMPS and a SMPS yielded good agreement between AMS and SMPS measurements, but a consistent mode diameter underestimation by the FMPS up to 40% in terms of volume size distribution was found. Using a simple correction method, the initial sizing underestimation was reduced to within a discrepancy of ~10%.
The work was supported by the University Grants Committee (Special Equipment Grant, SEG-HKUST07) and the Environmental Conservation Funds (ECF) of Hong Kong (project number: ECWW09EG04).