A new corona-based charger for aerosol particles

Medved, A.; Dorman, Frank D.; Kaufman, Stanley L.; Pöcher, Arndt

doi:10.1016/s0021-8502(00)90625-6

Cited by 71 publications

(65 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The counter-flow jets cause turbulence in the charging region (Medved et al 2000). The reason for higher charging rate of EAD for small-sized particles compared to large-sized particles is not identified in this study.…”

Section: Characterization Of Diffusion Chargers Using Nacl Particlesmentioning

confidence: 60%

See 1 more Smart Citation

Characterization of Aerosol Surface Instruments in Transition Regime

Jung

Kittelson

2005

Aerosol Science and Technology

106

View full text Add to dashboard Cite

The primary purpose of this study is to measure the size-and composition-dependent responses of aerosol surface instruments designed to measure surface area related properties. The secondary purpose of this study is to investigate the difference in charging rate between singlets (NaCl particles) and agglomerates (diesel particles) by using diffusion chargers. Agglomerates (diesel particles at engine load 75%) acquire more charge than singlets (NaCl particles) by 15 and 17% for LQ1-DC and EAD, respectively.

show abstract

Section: Characterization Of Diffusion Chargers Using Nacl Particlesmentioning

confidence: 60%

“…A PAS (PAS2000CE) (Kasper et al 2000) manufactured by EcoChem Analytics, a diffusion charger (LQ1-DC) manufactured by Matter Engineering AG, and a diffusion charger (EAD, model 3070A) (Medved et al 2000) manufactured by TSI were used for this study. These instruments all have a response time of 10 s or less.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Aerosol Surface Instruments in Transition Regime

Jung

Kittelson

2005

Aerosol Science and Technology

106

View full text Add to dashboard Cite

show abstract

“…A subsonic orifice accelerates the flow and forms a turbulent jet, which opposes a similar jet of aerosol particles formed by a second subsonic orifice. Particles are charged in the mixing zone of the two opposing jets (Medved et al 2000). After charging, particles are collected on a filter and an electrometer measures the current produced as they release their charge.…”

Section: Instrumentationmentioning

confidence: 99%

Application of a Diffusion Charger for the Measurement of Particle Surface Concentration in Different Environments

Ntziachristos

Polidori

Phuleria

et al. 2007

Aerosol Science and Technology

View full text Add to dashboard Cite

Particle surface area has recently been considered as a possible metric in an attempt to correlate particle characteristics with health effects. In order to provide input to such studies, two Nanoparticle Surface Area Monitors (NSAMs, TSI, Inc.) were deployed in different urban sites within Los Angeles to measure the concentration levels and the diurnal profiles of the surface area of ambient particles. The NSAM's principle of operation is based on the unipolar diffusion charging of particles. Results show that the particle surface concentration decreases from ∼150 µm 2 cm −3 next to a freeway to ∼100 µm 2 cm −3 at 100 m downwind of the freeway, and levels decline to 50-70 µm 2 cm −3 at urban background sites. Up to 51% and 30% of the total surface area corresponded to particles <40 nm next to the freeway and at an urban background site, respectively. The NSAM signal was well correlated with a reconstructed surface concentration based on the particle number size distribution measured with collocated Scanning Mobility Particle Sizers (SMPSs, TSI, Inc.). In addition, the mean surface diameter calculated by combination of the NSAM and the total particle number concentration measured by a Condensation Particle Counter (CPC, TSI, Inc.) was in reasonable agreement with the arithmetic mean SMPS diameter, especially at the urban site. This study corroborates earlier findings on the application of diffusion chargers for ambient particle monitoring by demonstrating that they can be effectively used to monitor the particle surface concentration, or Received 24 June 2006; accepted 9 February 2007. This research was supported by the Southern California Particle Center (SCPC), funded by EPA under the STAR program through Grant RD-8324-1301-0 to the University of Southern California and was also supported by the NIEHS-NIH grant no. ES-12243 and the California Air Resources Board (CARB) contract no. 03-329. We would also like to thank Dr. Manisha Singh (TSI Inc.) for availing the NSAM monitors and her assistance with the operation of these instruments. The research described herein has not been subjected to the EPA required peer and policy review and therefore does not necessarily reflect the views of the agency, and no official endorsement should be inferred. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.Address correspondence to Constantinos Sioutas, University of Southern California, Department of Civil and Environmental Engineering, 3620 S. Vermont Avenue, Los Angeles, CA 90089, USA. E-mail: sioutas@usc.edu combined with a CPC to derive the mean surface diameter with high temporal resolution.

show abstract

“…Aerosol particles are first introduced into a bipolar diffusion charger/neutralizer or a unipolar charger where they reach a known and stationary charge distribution in a short time. In the NanoScan, a patented opposed flow "unipolar" diffusion charger is used (Medved et al, 2000), while the PAMS uses a patented miniature dual-corona ionizer as the non-radioactive "bipolar" charger bringing the particles to steady-state charge distribution (Qi and Kulkarni, 2013). In the NanoScan's unipolar diffusion charger, unipolar ions from a corona discharge at a platinum needle tip and the aerosol flow in the opposite direction are swept through subsonic orifices to form turbulent jets.…”

mentioning

confidence: 99%

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

Hsiao

Lee

Chen

et al. 2016

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

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).

show abstract

A new corona-based charger for aerosol particles

Cited by 71 publications

References 4 publications

Characterization of Aerosol Surface Instruments in Transition Regime

Characterization of Aerosol Surface Instruments in Transition Regime

Application of a Diffusion Charger for the Measurement of Particle Surface Concentration in Different Environments

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

Contact Info

Product

Resources

About