Real-time characterization of ultrafine and accumulation mode particles in ambient combustion aerosols

Abstract

The diffusion charging sensor (DC), photoelectric aerosol sensor (PAS) and condensation particle counter (CPC) are real-time particle instruments that have time resolutions < 10s and are suitable for field use. This paper shows how the relative fraction of nuclei mode particles (D ≤ 50nm) in ambient combustion aerosols can be determined, along with the coverage degree of the respective accumulation mode particles with a modal diameter of ~ 100nm. Main tools for interpretation are the diameter of average surface DAve,S (obtained from CPC and DC measurements) and PAS/DC versus DAve,S scatter plots. Compared to the scanning mobility particle sizer (SMPS), which is a standard instrument for aerosol particle size distribution measurements, the presented method has a limited accuracy, but is substantially faster. Additionally, it is experimentally less demanding than SMPS measurements, especially for field applications.