Mass–Mobility Measurements Using a Centrifugal Particle Mass Analyzer and Differential Mobility Spectrometer

2013 ◽  
Vol 47 (11) ◽  
pp. 1215-1225 ◽  
Author(s):  
Tyler J. Johnson ◽  
Jonathan P. R. Symonds ◽  
Jason S. Olfert
Keyword(s):  
Particle Mass ◽  
Mass Analyzer ◽  
Differential Mobility ◽  
Differential Mobility Spectrometer

scholarly journals Tandem configuration of differential mobility and centrifugal particle mass analyzers for investigating aerosol hygroscopic properties

2016 ◽  
Author(s):  
Sergey S. Vlasenko ◽  
Hang Su ◽  
Ulrich Pöschl ◽  
Meinrat O. Andreae ◽  
Eugene F. Mikhailov
Keyword(s):  
Water Uptake ◽  
Aerosol Particles ◽  
Interaction Model ◽  
Particle Morphology ◽  
Particle Mass ◽  
Submicron Particles ◽  
Mass Analyzer ◽  
Hygroscopic Growth ◽  
Differential Mobility ◽  
Hygroscopic Properties

Abstract. A tandem arrangement of Differential Mobility Analyzer and Humidified Centrifugal Particle Mass Analyzer (DMA-HCPMA) was developed to measure the deliquescence and efflorescence thresholds and the water uptake of submicron particles over the relative humidity (RH) range from 10 % to 95 %. The hygroscopic growth curves obtained for Ammonium sulfate and sodium chloride test aerosols are consistent with thermodynamic model predictions and literature data. The DMA-HCPMA system was applied to measure the hygroscopic properties of urban aerosol particles, and the kappa mass interaction model (KIM) was used to characterize and parameterize the concentration-dependent water uptake observed in the 50–95 % RH range. For DMA-selected 160 nm dry particles (mass of 3.5 fg), we obtained a volume-based hygroscopicity parameter κv ≈ 0.2, which is consistent with literature data for freshly emitted urban aerosols. Overall, our results show that the DMA-HCPMA system can be used to measure size-resolved mass growth factors of atmospheric aerosol particles upon hydration and dehydration up to 95 % RH. The direct measurements of humidified particle mass allow avoiding complications that occur in the commonly used mobility-diameter-based HTDMA technique due to poorly defined particle morphology and density.

scholarly journals Measurements of particle masses of inorganic salt particles for calibration of cloud condensation nuclei counters

2009 ◽  
Vol 9 (1) ◽  
pp. 4653-4689 ◽  
Author(s):  
M. Kuwata ◽  
Y. Kondo
Keyword(s):  
Inorganic Salt ◽  
Cloud Condensation Nuclei ◽  
Input Parameter ◽  
Pitzer Model ◽  
Particle Mass ◽  
Mass Analyzer ◽  
Differential Mobility ◽  
Shape Factors ◽  
Critical Supersaturation ◽  
Dynamic Shape

Abstract. We measured the mobility equivalent critical dry diameter for CCN activation (dcme) and the particle mass of size-selected (NH4)2SO4 and NaCl particles to calibrate a CCN counter (CCNC) precisely. The CCNC was operated downstream of a differential mobility analyzer (DMA) for the measurement of dcme. The particle mass was measured using an aerosol particle mass analyzer (APM) operated downstream of the DMA. The measurement of particle mass was conducted for 50–150-nm particles. Effective densities (ρeff) of (NH4)2SO4 particles were 1.67–1.75 g cm−3, which correspond to the dynamic shape factors (χ) of 1.01–1.04. This shows that (NH4)2SO4 particles are not completely spherical. In the case of NaCl particles, ρeff was 1.75–1.99 g cm−3 and χ was 1.05–1.14, demonstrating that their particle shape was non-spherical. Using these experimental data, the volume equivalent critical dry diameter (dcve) was calculated, and it was used as an input parameter for calculations of critical supersaturation (S). Several thermodynamics models were used for the calculation of water activity. When the Pitzer model was employed for the calculations, the critical S calculated for (NH4)2SO4 and NaCl agreed to well within the uncertainty of 2% (relative). This result demonstrates that the use of the Pitzer model for the calibration of CCNCs gives the most probable value of S.

Sign in / Sign up

Export Citation Format

Share Document