Evaluation of Fast Mobility Particle Sizer (FMPS) for Ambient Aerosol Measurement

Abstract

Fast Mobility Particle Sizer (FMPS) size distribution measurements with different inversion matrices were compared with the Scanning Mobility Particle Sizer (SMPS) for ambient aerosols sampled from a background location in Riverside, CA in this study. The FMPS-compact matrix showed the best agreement with SMPS for particle concentration in the size ranges of 9-359 nm and 9-100 nm (for ultrafine particles). The FMPS-compact matrix also showed the best agreement with the SMPS for mode diameter. All FMPS inversion matrices showed size-dependent discrepancies compared with the SMPS. Measurement of the nonvolatile fraction of ambient aerosol downstream of a catalytic stripper showed that the FMPS-compact matrix agreed best with the SMPS with the FMPS over SMPS linear regression slope of 0.99-1.00 for particle concentrations. This is likely due to the restructuring of soot during the removal of volatile coating. This study showed that the soot and compact matrices are insufficient for ambient aerosol measurement. Challenges remain for FMPS measurements when particle morphologies are not known a priori or when they are different from near spherical shape or aggregate structure.

Comparison of Particle Sizers and Counters with Soot-like, Salt, and Silver Particles

“…To put the results of this study into perspective, Figure 8 summarizes the results of other studies from the literature with similar materials and sizes: silver [83], salt [15,44,45,84,85], vehicle exhaust [25,26,44,45,86,87], and ambient [25,26,88,89]. Table A1 in Appendix A presents the reference instruments, the particle materials, the GMD, and the concentration of aerosols used in these studies.…”

“…All studies used the "Default" EEPS matrix, except those with a black frame that used the "Soot" EEPS matrix. Data from: silver [83], salt [15,44,45,84,85], vehicle exhaust [25,26,44,45,86,87], and ambient [25,26,88,89].…”

Measurement of Particulate Matter: Principles and Options of Measurement at Present

“…Then the particles pass through a cylindrical electrostatic classifier. The outer wall of the classifier consists of a series of electrically isolated rings connected to sensitive electrometers [28], [37], [40]. Aerodynamic Particle Sizer (APS) (Fig.…”