Articles | Volume 18, issue 17
https://doi.org/10.5194/amt-18-4397-2025
https://doi.org/10.5194/amt-18-4397-2025
Research article
 | 
10 Sep 2025
Research article |  | 10 Sep 2025

Improving the accuracy in particle concentration measurements of a balloon-borne optical particle counter, UCASS

Sina Jost, Ralf Weigel, Konrad Kandler, Luis Valero, Jessica Girdwood, Chris Stopford, Warren Stanley, Luca K. Eichhorn, Christian von Glahn, and Holger Tost

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Cited articles

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Short summary
For the balloon-borne detection of particles (diameter 0.4 < Dp < 40 µm), the Universal Cloud and Aerosol Sounding System (UCASS) was used, whose sample flow is determined by GPS-measured ascent rates. In flights, actual UCASS sample flows rarely match the ascent rates. Errors are minimised by real-time detection of the UCASS flows, e.g. by implementing a thermal flow sensor (TFS) within the UCASS. The TFSs were tested in flight and calibrated at up to 10 m s−1 and at variable angles of attack.
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