Abstract View
A Mobility Particle Size Spectrometer to Access the 1nm Particle Size Range: The PSMPS
GERHARD STEINER, Joonas Vanhanen, Joonas Enroth, Lothar Keck, Minna Väkevä, Grimm Aerosol Technik Ainring
Abstract Number: 416
Working Group: Instrumentation and Methods
Abstract
Here, we present the final, commercially available, version of a mobility particle size spectrometer that is able to access the 1 nm particle size range for ambient atmospheric measurements. The instrument originates from a collaboration of Grimm Aerosol Technik, Germany and Airmodus Ltd, Finland, combining a Grimm SMPS+C system with the Airmodus Particle Size Magnifier (PSM). Accordingly, it is named: PSMPS. The main system components are: a modified version of the short Grimm Differential Mobility Analyzer (Grimm S-DMA), the diethylene glycol-based PSM (Airmodus A10) and the new butanol-based CPC (Grimm 5417). The modified S-DMA is specially optimized for the transmission of small ions. Typically, it is operated with an aerosol sample flow rate of 2.5 L/min and a sheath flow rate of 10 L/min, allowing size distribution measurements from 1.1-55.7 nm. The PSM is used to lower the detection efficiency of the Grimm CPC below 2 nm in electrical mobility equivalent diameter. The new Grimm 5417 CPC is an upgraded version of the well-known 5416 CPC, that features two switchable aerosol sample flow rates of 0.3 and 0.6 L/min and also supplies the S-DMA with sheath airflow rates of either 3.0 or 10.0 L/min. The overall system performance was tested in a multitude of laboratory experiments, determining various size dependent parameters like: DMA’s transfer function, DMA penetration efficiency, PSM and CPC counting efficiency. With the knowledge of these parameters, we are able to define a well-known overall system performance. In this presentation, we will introduce the features and performance of the PSMPS system and will highlight some laboratory and ambient aerosol number size distribution measurements.