Comparison ofthe Novosibirsk automated diffusion battery with the Vienna electro mobility spectrometer

Reischl, G.; Majerowicz, A.; Ankilow, A; Eremenko, S.I.; Mavliev, Rashid

doi:10.1016/s0021-8502(05)80103-x

“…This type of instrument has not yet been commercialized. It was described rst by Kogan and Burnashova (1960) and was further developed in different versions by Okuyama et al (1984), Ankilov et al (1991), Kousaka (1993), and Mavliev and Wang (2000). The major advantage of the turbulent mixing CNC (TMCNC) is the exibility of generating supersaturation by simply mixing the aerosol ow and a ow saturated with the working uid vapor.…”

Section: Introductionmentioning

confidence: 99%

A Transition from Heterogeneous to Homogeneous Nucleation in the Turbulent Mixing CNC

Mavliev¹,

Hopke²,

Wang³

et al. 2001

Aerosol Science and Technology

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A new method for changing the supersaturation in the Turbulent Mixing CNC has been developed and used to examine the transition from heterogeneous nucleation of test particles to homogenous nucleation of working uid: dibutylphthlate (DBP). Supersaturation was controlled by changing the DBP vapor pressure in the nozzle ow by saturating only a predetermined part of the ow, while the total ow and temperature remain constant. This approach allows for the changing of the initial DBP vapor pressure, while keeping the ow structure and temperature eld unchanged. The DBP concentration in the outlet of the vapor generator was measured experimentally for different ratios of saturated and bypass ows and found to be close to estimated values. Experimental results for transitions from heterogeneous nucleation to homogeneous nucleation are presented for NaCl and WO x particles at various DBP vapor pressures. With an increasing of the DBP vapor pressure, the concentration of enlarged particles increases until it reaches a plateau. At higher initial values of DBP pressure, homogeneous nucleation prevails, and the number concentration of particles follows a curve typical for homogeneous nucleation recorded in the absence of nuclei. Nuclei with different mobility diameters were activated at different values of vapor pressure. There are signi cant differences in the slopes of particle activation curves for NaCl and WO x particles. The reasons for such differences are a subject for continuing research.

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“…CNC sensitivities, as characterized by their d 50 values, are typically 10-20 nm and instruments with a d 50 as low as 3 nm have also been developed (Okuyama et al 1984;Ankilov et al 1991;Stolzenburg and McMurry 1991;Mavliev et al 1996). Supersaturation was generated in early CNCs by a sudden expansion of the sample air and typically used water as the working uid.…”

Section: Introductionmentioning

confidence: 99%

Design and Characterization of a New, Water-Based, High Sample-Flow Condensation Nucleus Counter

Parsons¹,

Mavliev²

2001

Aerosol Science and Technology

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We describe the development and performance of a new, continuous-ow, single-particle, condensation nucleus counter (CNC) that uses water as its working uid. Supersaturation is generated both through mixing of the ambient temperature sample gas stream with a hot saturated gas stream and by cooling of this mixed gas stream. Nucleation and condensation upon the entrained particles occurs within a cooled growth tube and a laser-based optical counter detects the enlarged particles. This Modi ed-Mixing CNC (MMCNC) samples gas at 0.5 cfm (14.1 lpm), has a false count rate of 0.012/cf, and has a unity counting ef ciency for NaCl particles larger than 12 nm in diameter. These attributes make it an ideal instrument for next-generation cleanroom monitoring, where it can be plumbed into an existing DI water line and run without the need for frequent maintenance. Its use of water and high ow rate may also give it a unique advantage for atmospheric and indoor air research applications. We characterize the MMCNC's performance by varying four critical variables affecting its operation. A simple model accounting for heat and mass transfer to the growth tube is successful at predicting the relative importance of each of these variables and in estimating the average supersaturation in the growth tube.

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“…Thus the sensitivity of a CNC is directly related to the value of S achieved. CNC sensitivities, as characterized by their d 50 values, are typically 10-20 nm and instruments with a d 50 as low as 3 nm have also been developed (Okuyama et al 1984;Ankilov et al 1991;Stolzenburg and McMurry 1991;Mavliev et al 1996). Supersaturation was generated in early CNCs by a sudden expansion of the sample air and typically used water as the working uid.…”

Section: Introductionmentioning

confidence: 99%

Design and Characterization of a New, Water-Based, High Sample-Flow Condensation Nucleus Counter

Parsons¹,

Mavliev²

2001

Aerosol Science and Technology

0

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We describe the development and performance of a new, continuous-ow, single-particle, condensation nucleus counter (CNC) that uses water as its working uid. Supersaturation is generated both through mixing of the ambient temperature sample gas stream with a hot saturated gas stream and by cooling of this mixed gas stream. Nucleation and condensation upon the entrained particles occurs within a cooled growth tube and a laser-based optical counter detects the enlarged particles. This Modi ed-Mixing CNC (MMCNC) samples gas at 0.5 cfm (14.1 lpm), has a false count rate of 0.012/cf, and has a unity counting ef ciency for NaCl particles larger than 12 nm in diameter. These attributes make it an ideal instrument for next-generation cleanroom monitoring, where it can be plumbed into an existing DI water line and run without the need for frequent maintenance. Its use of water and high ow rate may also give it a unique advantage for atmospheric and indoor air research applications. We characterize the MMCNC's performance by varying four critical variables affecting its operation. A simple model accounting for heat and mass transfer to the growth tube is successful at predicting the relative importance of each of these variables and in estimating the average supersaturation in the growth tube.

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Comparison ofthe Novosibirsk automated diffusion battery with the Vienna electro mobility spectrometer

Cited by 33 publications

References 6 publications

A Transition from Heterogeneous to Homogeneous Nucleation in the Turbulent Mixing CNC

A Transition from Heterogeneous to Homogeneous Nucleation in the Turbulent Mixing CNC

Design and Characterization of a New, Water-Based, High Sample-Flow Condensation Nucleus Counter

Design and Characterization of a New, Water-Based, High Sample-Flow Condensation Nucleus Counter

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