Characterization of a Kanomax® fast condensation particle counter in the sub-10 nm range

Abstract A butanol-based fast condensation particle counter (Fast CPC, Model 3650, Kanomax Inc., Japan) was characterized in this study with three different types of monodisperse particles, including positively and negatively charged nickel-chromium (Ni/Cr) particles, positively charged tetraheptyl ammonium bromide (THABr) and tetrabutyl ammonium bromide (TBABr) particles, and positively charged polyethylene glycol (PEG) particles. The PEG particles were characterized with varied numbers of charges, whereby the charge number effect on particle activation was investigated. The performance of the Fast CPC was compared with a TSI® 3775 CPC and a TSI® 3776 CPC, respectively, under both factory temperature settings and boosted temperature settings, the latter of which corresponded to the brink of butanol homogeneous nucleation. Our results show that size-resolved Ni/Cr particles were detected by the Fast CPC with comparable detection efficiencies regardless of the charge polarity. When the charge number on a PEG particle increased from 1 to 3, an increasing tendency of the detection efficiency was observed, hinting that multiple charges on a particle will facilitate its activation. Particle activation was affected by the particle chemical composition as well, which is suggested by the higher activation efficiencies of PEG particles than those of Ni/Cr particles. The effects of multiple charges and chemical composition on particle activation were both more significant under factory temperature settings, but became less pronounced under boosted temperature settings. In addition to a quicker response time, the Fast CPC was capable of detecting sub-3 nm particles under boosted temperature settings, with the detection efficiency higher than that of the 3775 CPC but lower than that of the 3776 CPC, and can be used as a good candidate for the measurement of rapidly varying concentrations of small particles.