Articles | Volume 10, issue 4
Research article
02 May 2017
Research article |  | 02 May 2017

A DMA-train for precision measurement of sub-10 nm aerosol dynamics

Dominik Stolzenburg, Gerhard Steiner, and Paul M. Winkler

Abstract. Measurements of aerosol dynamics in the sub-10 nm size range are crucially important for quantifying the impact of new particle formation onto the global budget of cloud condensation nuclei. Here we present the development and characterization of a differential mobility analyzer train (DMA-train), operating six DMAs in parallel for high-time-resolution particle-size-distribution measurements below 10 nm. The DMAs are operated at six different but fixed voltages and hence sizes, together with six state-of-the-art condensation particle counters (CPCs). Two Airmodus A10 particle size magnifiers (PSM) are used for channels below 2.5 nm while sizes above 2.5 nm are detected by TSI 3776 butanol-based or TSI 3788 water-based CPCs. We report the transfer functions and characteristics of six identical Grimm S-DMAs as well as the calibration of a butanol-based TSI model 3776 CPC, a water-based TSI model 3788 CPC and an Airmodus A10 PSM. We find cutoff diameters similar to those reported in the literature. The performance of the DMA-train is tested with a rapidly changing aerosol of a tungsten oxide particle generator during warmup. Additionally we report a measurement of new particle formation taken during a nucleation event in the CLOUD chamber experiment at CERN. We find that the DMA-train is able to bridge the gap between currently well-established measurement techniques in the cluster–particle transition regime, providing high time resolution and accurate size information of neutral and charged particles even at atmospheric particle concentrations.

Short summary
Aerosol particles produced by gas-to-particle conversion in the atmosphere might influence the climate due to their effects on cloud formation. Characterizing the early growth of newly formed particles is extremely challenging. We present the development and characterization of an instrument that measures the evolution of particles smaller than 10 nm with high time resolution and/or high sensitivity to low concentrations. It can help quantify the characteristics of early nanoparticle growth.