A laboratory comparison of real-time measurement methods for 10-100-nm particle size distributions

Abstract

We present information regarding the relative performance of five TSI particle sizing instruments when presented with several log-normally distributed particle populations that vary in terms of composition, concentration, and modal mean diameter (in the range of 10-100 nm) in a controlled laboratory environment. In experiments conducted with NaCl, NaNO3, and organic aerosols, across a total particle concentration suite ranging from approximately 1 × 104 cm-3 to 1 × 106 cm -3, total number concentrations of sub-100-nm diameter particles from four SMPS systems and an FMPS all fall within ±50% of each other (and generally are within ±30%). However, larger discrepancies are evident in the particle size distribution, particularly for the NaCl particles, with an SMPS operated with a water-based CPC exhibiting large negative bias in modal peak concentrations relative to the isobutanol-based SMPS systems and the FMPS. Much closer agreement is found for NaNO3 particles, although the SMPS systems tended to exhibit higher modal peak concentrations, and a slight shifting toward lower modal peak diameter than the FMPS. © American Association for Aerosol Research.