First Differential Mobility Analysis (DMA) Measurements of Air Ions Produced by Radioactive Source and Corona

Alonso, M.; Santos, J. P.; Hontañón, Esther; Ramiro, Emilio

doi:10.4209/aaqr.2009.05.0033

Cited by 22 publications

(21 citation statements)

References 19 publications

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“…In general, the negative ions were smaller than 1.6 nm (0.8 cm 2 V −1 s −1 ) in all conditions when measured with the HDMA, whereas the positive ions were below 1.7 nm (0.7 cm 2 V −1 s −1 ). These results are in good agreement with the NAIS corona charger experiments by Asmi et al (2009), and other corona charger experiments (Nagato and Owaga, 1998;Hernandez-Sierra et al, 2003;Alonso et al, 2009).…”

Section: Size Distribution Of Corona-generated Ionssupporting

confidence: 81%

“…5) agree well with the corona-generated ion size distributions observed by e.g. Nagato and Owaga, 1998;Alonso et al 2009;Asmi et al, 2009;and Junninen et al, 2009. Based on their data, positive and negative ions had approximately five and two peaks in the mobility spectra, respectively, when filtered (also dried with silica gel in Alonso et al 2009) room air was used as the carrier gas.…”

Section: Effect Of Carrier Gassupporting

confidence: 79%

“…Nagato and Owaga, 1998;Alonso et al 2009;Asmi et al, 2009;and Junninen et al, 2009. Based on their data, positive and negative ions had approximately five and two peaks in the mobility spectra, respectively, when filtered (also dried with silica gel in Alonso et al 2009) room air was used as the carrier gas. On the contrary, we detected size distributions with two peaks for positive ions and approximately five peaks for negative ions (Fig.…”

Section: Effect Of Carrier Gasmentioning

confidence: 99%

“…Tamm et al, 1992;Hernandez-Sierra, 2003;Biskos et al, 2005;Tippayawong, 2009, 2010). The size and number concentration of small ions formed inside the charger have been characterised for some corona chargers (Tamm et al, 1992;Nagato and Owaga, 1998;HernandezSierra et al, 2003;Alonso et al, 2009). The chemical composition of these ions depends on trace gas compounds and residence time (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Characterisation of corona-generated ions used in a Neutral cluster and Air Ion Spectrometer (NAIS)

et al. 2011

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Abstract. We characterized size and chemical composition of ions generated by a corona-needle charger of a Neutral cluster and Air Ion Spectrometer (NAIS) by using a high resolution differential mobility analyzer and a time-of-flight mass spectrometer. Our study is crucial to verify the role of corona-generated ions in the particle size spectra measured with the NAIS, in which a corona charger is used to charge aerosol particles down to the size range overlapping with the size of generated ions. The size and concentration of ions produced by the corona discharging process depend both on corona voltage and on properties and composition of carrier gas. Negative ions were <1.6 nm (0.8 cm 2 V −1 s −1 in mobility) in all tested gas mixtures (nitrogen, air with variable mixing ratios of water vapour), whereas positive ions were <1.7 nm (0.7 cm 2 V −1 s −1 ). Electrical filtering of the corona generated ions and not removing all charged particles plays an important role in determining the lowest detection limit. Based on our experiments, the lowest detection limit for the NAIS in the particle mode is between 2 and 3 nm.

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Section: Size Distribution Of Corona-generated Ionssupporting

confidence: 81%

Section: Effect Of Carrier Gassupporting

confidence: 79%

Section: Effect Of Carrier Gasmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterisation of corona-generated ions used in a Neutral cluster and Air Ion Spectrometer (NAIS)

et al. 2011

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“…Am and corona discharge as a function of the applied voltage and polarity (Alonso et al, 2009). Recently, two portable particle size distribution analyzers (TSI NanoScan SMPS, 3910, USA and Kanomax PAMS, 3300, Japan) were introduced to the market.…”

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.

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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).

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Indoor and outdoor atmospheric ion mobility spectra, diurnal variation, and relationship with meteorological parameters

Wright

Holden

Shallcross

et al. 2014

J. Geophys. Res. Atmos.

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We report measurements of small ion mobility spectra and concentrations made over a 5 month period using a Gerdien-type ion mobility spectrometer at one indoor site in central Bristol, UK, and one indoor and one outdoor site in a semirural area. We assess the diurnal variation in ion concentration and mobility, variability with meteorological parameters, and features within the ion mobility spectra. Ion concentration (typically in the range 100-1000 cm À3 ) was highest overnight and lowest in late morning and afternoon. Total conductivity also followed this trend suggesting that small ions contribute more to conductivity than larger charged particles, although at the semirural site, indoor activity produced charged aerosol intermittently, while infiltration of outdoor aerosol contributed at the urban site. Negative ion mobility (typically 1.6-1.9 cm 2 V À1 s À1 ) was higher overnight than at other times, while positive ion mobility (typically 1.2-1.4 cm 2 V À1 s À1 ) showed no diurnal variability. In general, temperature, pressure, wind speed, and water vapor pressure were inversely related to both concentration and mobility, except outdoors when (negative) mobility increased with increasing temperature and pressure, while increased relative humidity was associated with higher ion mobilities and concentrations. Analysis of high-resolution mobility spectra revealed several mobilities for each polarity at which peaks were identified across all sites, suggesting similarity in composition but with varying importance at each site. Intermediate ions (mobilities 0.2-0.3 cm 2 V À1 s À1 ) were observed at the outdoor site, but individual nucleation events which may be associated with them were not identifiable.

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First Differential Mobility Analysis (DMA) Measurements of Air Ions Produced by Radioactive Source and Corona

Cited by 22 publications

References 19 publications

Characterisation of corona-generated ions used in a Neutral cluster and Air Ion Spectrometer (NAIS)

Characterisation of corona-generated ions used in a Neutral cluster and Air Ion Spectrometer (NAIS)

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

Indoor and outdoor atmospheric ion mobility spectra, diurnal variation, and relationship with meteorological parameters

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