Size resolution of the Airmodus A10 particle size magnifier with purified clusters

Abstract

Brilke et al. (2020) have recently characterized several commercial condensation particle counters (CPCs) based on clusters of tetraheptylammonium bromide and tetrabutylammonium iodide. These seed particles were generated by a bipolar electrospray source (BES) and purified by high resolution mobility separation. Paradoxically, their results suggest that the size resolution achievable by scanning over CPC supersaturation is less than previously found with other aerosol sources, even though the BES tends to produce particles with singular shape and composition homogeneity. Here we report activation curves for the Airmodus A10 Particle Size Magnifier, tested with a diversity of mobility classified clusters, produced by a BES from the salts EMI-bis(trifluoromethylsulfonyl)imide and EMI-tris(pentafluoroethyl)trifluorophosphate (EMI = 1-Ethyl-3-methylimidazolium). We find activation curves several times steeper than those of Brilke et al.