Experimental Comparison of Two Portable and Real-Time Size Distribution Analyzers for Nano/Submicron Aerosol Measurements

Abstract

Two portable, battery powered particle size distribution analyzers, TSI NanoScan scanning mobility particle sizer (TSI NanoScan SMPS 3910, USA) and Kanomax Portable Aerosol Mobility Spectrometer (Kanomax PAMS 3300, Japan), have been recently introduced to the market. Both are compact and allow researchers to rapidly measure and monitor ambient or indoor ultrafine and nanoparticles in real time. In addition, both instruments apply the SMPS measuring scheme, utilizing a corona charger in place of a radioactive neutralizer, and are integrated with a hand-held condensation particle counter (CPC). In this study, the different designs, flow schemes, and operational settings of both instruments have been summarized based on the information released by the manufacturers and the available published literature. The performance characteristics and monitoring capability of these two portable ultrafine to nanoparticle sizers were investigated and compared to a reference TSI 3936 lab-based SMPS under identical conditions. Reasonable agreement was found between the three instruments in terms of their efficiency in sizing and counting polydispersed particles. Of the two portable analyzers, PAMS was able to provide a higher sizing resolution for monodispersed particle measurements than NanoScan, when operated under the High Mode (higher sheath to aerosol flow ratio).

Using Building Energy and Smart Thermostat Data to Evaluate Indoor Ultrafine Particle Source and Loss Processes in a Net-Zero Energy House

“…Indoor particle number size distributions (cm –3 ) were measured continuously (24 h per day) with a scanning mobility particle sizer (SMPS, electrical mobility diameter ( D em ) range: 10 to 300 nm) (Model 3910, TSI Inc.) and an optical particle sizer (OPS, optical diameter ( D o ) range: 300 to 10 000 nm) (Model 3330, TSI Inc.) at 1 min time resolution. Particle number size distributions from D em = 150 to 300 nm were estimated through spline interpolation due to operational limitations of the SMPS. − The SMPS and OPS were located on floor 1 between the kitchen and the living room, with sample inlets 1.5 m above the floor. Measured particle number size distributions were translated to surface area (μm 2 cm –3 ) and volume (μm 3 cm –3 ) size distributions assuming spherical particles (dynamic shape factor: χ = 1) and mass size distributions (μg m –3 ) using measured size-resolved effective densities (ρ eff ) for indoor particles in the ReNEWW House (Figure S5), following the work of Wu and Boor (2020) .…”

The Aerosol Research Observation Station (AEROS)

“…In the operation of the OPS, the particle density is assumed as 1 g cm -3 , and no information on the reflective index is added, as there is very limited knowledge of the atmospheric particle chemical and mineralogical composition in this region (Gill et al, 2000; and, therefore, no way to correctly capture the particles' density or refractive index, which are needed to convert the optical concentration to aerodynamic sizes. The OPS has been used previously in many laboratory settings (Ardon-Dryer et al, 2015;Yamada et al, 2015;Hsiao et al, 2016) and indoor experiments (Mølgaard et al, 2015;Maragkidou et al, 2018;Wang et al, 2020). Several studies that examined the performance of the OPS under diverse laboratory conditions have found it to be comparable with various reference units (Ardon-Dryer et al, 2015;Vasilatou et al, 2021).…”

Determination of the Concentration of Ultrafine Aerosol Using an Ionization Sensor

“…Moreover, cascade impactors can be used to sample different aerosol fractions down to ultrafine particles [ 26 ]. The disadvantages of the counter methods are their relativity (the effect of which is the discrepancy between the indications of two different instruments) and the lack of appropriate methods of calibration [ 21 , 27 , 28 ]. The disadvantages of gravimetric methods are their low accuracy (which depends on the sensitivity of the scale), long analysis time (depending on weighing procedures, filter conditioning), and susceptibility to physical stimuli (shock, vibrations, handling by an analyst).…”