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The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus

Maximum uncertainties for the calculated charging probabilities for different ion properties. For decreasing particle size, the uncertainties increase more and more with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions. The “hump” in the data for positive polarity originates from a glancing intersection of the minimum and maximum dataset.
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f0045: Maximum uncertainties for the calculated charging probabilities for different ion properties. For decreasing particle size, the uncertainties increase more and more with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions. The “hump” in the data for positive polarity originates from a glancing intersection of the minimum and maximum dataset.

Mentions: Nevertheless, Fig. 9 shows the maximum uncertainties for the calculated charging probabilities of aerosols, calculated as the mean difference of the most extreme datasets for the ions with different properties. At large particle sizes of 100 nm, the differences between the calculated charging probabilities vanish and converge into each other. For decreasing particle size, the uncertainties increase with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions.


The effect of carrier gas contaminants on the charging probability of aerosols under bipolar charging conditions.

Steiner G, Reischl GP - J Aerosol Sci (2012)

Maximum uncertainties for the calculated charging probabilities for different ion properties. For decreasing particle size, the uncertainties increase more and more with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions. The “hump” in the data for positive polarity originates from a glancing intersection of the minimum and maximum dataset.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3473358&req=5

f0045: Maximum uncertainties for the calculated charging probabilities for different ion properties. For decreasing particle size, the uncertainties increase more and more with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions. The “hump” in the data for positive polarity originates from a glancing intersection of the minimum and maximum dataset.
Mentions: Nevertheless, Fig. 9 shows the maximum uncertainties for the calculated charging probabilities of aerosols, calculated as the mean difference of the most extreme datasets for the ions with different properties. At large particle sizes of 100 nm, the differences between the calculated charging probabilities vanish and converge into each other. For decreasing particle size, the uncertainties increase with a maximum value of ±8.1% for negative ions and ±6.3% for positive ions.

Bottom Line: A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses.Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols.The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Wien, Austria ; Department of Physics, University of Helsinki, P.O. Box 64, 00014, Finland.

ABSTRACT
This work concentrates on the experimental determination of the properties of ionic molecular clusters that are produced in the bipolar ionic atmosphere of a radioactivity based (241)Am charger. The main scope of this study was to investigate the dependency of the ions' properties on carrier gas contaminants caused by the evaporation of trace gases from different kinds of frequently encountered tubing materials. A recently developed high resolution mobility spectrometer allows the precise determination of the ions' electrical mobility; an empirical mass-mobility relationship was used to approximate the corresponding ion masses. It was found that impurities in the carrier gas dramatically change the pattern of the ion mobility/size distribution, resulting in very different ion properties that strongly depend on the carrier gas composition. Since the ion properties control the charging process of aerosols, it was further investigated how the different ion properties affect the calculation of the charging probabilities of aerosols. The results show that despite large variations of the ions' properties, only a minor effect on the calculated charging probabilities can be found.

No MeSH data available.


Related in: MedlinePlus