Technical Note: Using DEG-CPCs at upper tropospheric temperatures

摘要: Abstract. Over the last few years, several condensation particle counters (CPCs) capable of measuring in sub-3 nm size range have been developed. Here we study performance CPCs based on diethylene glycol (DEG) at different temperatures during Cosmics Leaving OUtdoor Droplets (CLOUD) measurements CERN. The data shown here are first set verification for under upper tropospheric using atmospherically relevant aerosol particles. To put results perspective calibrated DEG-CPC room temperature, resulting a cut-off diameter 1.4 nm. All diameters refer to mobility equivalent this paper. At ranging from 246.15 K 207.15 K, found sizes relative magnifier 2.5 2.8 Due low number concentration after classification, high uncertainty (±0.3 nm) associated with them. Operating two laminar flow DEG-CPCs together other instruments, looked growth rates population CLOUD chamber particles smaller than 10 temperatures. A more consistent picture emerged when normalized fixed gas-phase sulfuric acid concentration. instruments detected larger lower temperatures, and observed decreased as function showing similar trend all instruments. theoretical calculations had but much temperature dependency.