Articles | Volume 10, issue 6
Atmos. Meas. Tech., 10, 2271–2281, 2017
Atmos. Meas. Tech., 10, 2271–2281, 2017

Research article 19 Jun 2017

Research article | 19 Jun 2017

Characterization of three new condensation particle counters for sub-3 nm particle detection during the Helsinki CPC workshop: the ADI versatile water CPC, TSI 3777 nano enhancer and boosted TSI 3010

Juha Kangasluoma1, Susanne Hering2, David Picard3, Gregory Lewis2, Joonas Enroth1, Frans Korhonen1, Markku Kulmala1, Karine Sellegri3, Michel Attoui1,4, and Tuukka Petäjä1 Juha Kangasluoma et al.
  • 1Department of Physics, P.O. Box 64, 00014, University of Helsinki, Helsinki, Finland
  • 2Aerosol Dynamics Inc., Berkeley, CA, USA
  • 3Laboratoire de Météorologie Physique, UMR6016, Observatoire de Physique du Globe de Clermont-Ferrand, CNRS, Université Blaise Pascal, Clermont-Ferrand, France
  • 4University of Paris Est Créteil, University of Paris Diderot, LISA, UMR CNRS 7583, France

Abstract. In this study we characterized the performance of three new particle counters able to detect particles smaller than 3 nm during the Helsinki condensation particle counter (CPC) workshop in summer 2016: the Aerosol Dynamics Inc. (ADI; Berkeley, USA) versatile water condensation particle counter (vWCPC), TSI 3777 nano enhancer (TSI Inc., Shoreview, USA) and modified and boosted TSI 3010-type CPC from Université Blaise Pascal called a B3010. The performance of all CPCs was first measured with charged tungsten oxide test particles at temperature settings which resulted in supersaturation low enough to not detect any ions produced by a radioactive source. Due to similar measured detection efficiencies, additional comparison between the 3777 and vWCPC were conducted using electrically neutral tungsten oxide test particles and with positively charged tetradodecylammonium bromide. Furthermore, the detection efficiencies of the 3777 and vWCPC were measured with boosted temperature settings yielding supersaturation which was at the onset of homogeneous nucleation for the 3777 or confined within the range of liquid water for the ADI vWCPC. Finally, CPC-specific tests were conducted to probe the response of the 3777 to various inlet flow relative humidities, of the B3010 to various inlet flow rates and of the vWCPC to various particle concentrations. For the 3777 and vWCPC the measured 50 % detection diameters (d50s) were in the range of 1.3–2.4 nm for the tungsten oxide particles, depending on the particle charging state and CPC temperature settings, between 2.5 and 3.3 nm for the organic test aerosol, and in the range of 3.2–3.4 nm for tungsten oxide for the B3010.

Short summary
The manuscript presents a characterization of three new particle counters able to detect airborne nanoparticles smaller than 3 nm in diameter. We explored some of the parameters affecting the smallest detectable particle size, such as sample flow relative humidity, the particle chemical composition and the electrical charging state. The characterization results help one to select a suitable particle counter for a given application.