Theory and calibration of a screen-type diffusion battery

Cheng, Yung‐Sung; Keating, J.A.; Kanapilly, G.M.

doi:10.1016/0021-8502(80)90127-5

Cited by 101 publications

(18 citation statements)

References 8 publications

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“…The parallel flow diffusion battery is based on the screen diffusion battery theory as developed by Cheng (Cheng et al, 1980). Cheng used the fan model filter to describe the penetration of aerosols through the diffusion battery screens.…”

Section: Parallel-flow Diffusion Batterymentioning

confidence: 99%

Size Characterization of Carbonaceous Particles Using a Lovelace Multijet Cascade Impactor / Parallel-Flow Diffusion Battery Serial Sampling Train

Barr

Cheng

Yeh

et al. 1989

Aerosol Science and Technology

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A serial sampling train consisting of a Lovelace multijet cascade impactor (LMJI) and a seven cell parallel-flow diffusion battery (PFDB) has been used to provide a comprehensive method for suing aerosols with a wide size distribution ranging from less than 0.01 pm to over 10 pm. The fraction of the aerosol greater than 0.7 pm is collected by the impactor. The remaining fraction of the aerosol is sampled by the PFDB. Design of the PFDB is based on the theory of a screen-type diffusion battery. The concept of parallel flow is employed to provide a method for sampling aerosols that fluctuate too rapidly in concentration and size distribution to be measured by conventional methods. The LMJI/PFDB sampling system is useful for characterizing multimodel sue distributions such as those that occur in ambient aerosols. It can also be used to determine the chemical composition of collected samples as a function of particle size. This sampling system has been used to size classify diesel and diesel-oil shale exposure atmospheres, and benzo(a)-pyrene-coated carbon black aerosols. The diffusion equivalent diameter (D,,) of the diesel exhaust was 0.07-0.08 pm, and the oil-shale dust had a mass median aerodynamic diameter (MMAD) of 2.6-2.9 pm. The size distribution of the carbon black aerosol was bimodal, with the fine fraction having a D, , of 0.2 pm, and the coarse fraction having a MMAD of 2.0 pm.

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Section: Parallel-flow Diffusion Batterymentioning

confidence: 99%

Size Characterization of Carbonaceous Particles Using a Lovelace Multijet Cascade Impactor / Parallel-Flow Diffusion Battery Serial Sampling Train

Barr

Cheng

Yeh

et al. 1989

Aerosol Science and Technology

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“…A wire screen with a mesh size of 625 μm was applied as the sampling substrate for the measurement of unattached decay products (Meisenberg and Tschiersch, 2009). With the given airflow rate, this screen features a negligible deposition probability for attached decay products, whereas unattached decay products are sampled with an efficiency of about 40%, which was calculated according to Cheng et al. (1980).…”

Section: Methodsmentioning

confidence: 99%

Thoron in indoor air: modeling for a better exposure estimate

Meisenberg

Tschiersch

2010

Indoor Air

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The radioactive noble gas radon with its decay products is well known as a health risk. After increased concentrations of the isotope (220)Rn (thoron) have been found in traditional Chinese mud-walled cave dwellings, the need for a model that describes the occurrence of thoron and its decay products indoors has arisen. This work presents such a model from the emergence of thoron in the building material until the decay to the stable (208)Pb and discusses the various influences on the occurrence of these nuclides. The model makes possible to predict the exposure of people staying in a room to thoron and its decay products and--combined with a dose model--to calculate their inhalation doses from easily measurable data.

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“…Monodisperse aerosols were split into two streams. The first aerosol stream (3.5 L/min) went to a Faraday cup/electrometer (model 610B, Keithley Instruments) whose counting efficiency was assumed to be 1 (Cheng et al, 1980). The second aerosol stream (0.5 FIGURE 1.…”

Section: Methodsmentioning

confidence: 99%

Counting Efficiency of the TSI Model 3020 Condensation Nucleus Counter

Cheng

Newton

et al. 1990

Aerosol Science and Technology

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The counting efficiency of the TSI model 3020 condensation nucleus counter (CNC) was determined as a function of aerosol flow rate and trigger level using aerosols of known size and an aerosol electrometer. When the aerosol flow rate dropped from 300 to 200 mL/min, counting efficiencies increased significantly in the single-particle counting mode for particles with diameter < 20 nm while those for larger particles remained constant. However, the photometric mode counting efficiency for particles with diameter > 20 nm increased and exceeded unity. When the aerosol flow rate was reduced to 100 mL/min, the counting efficiencies for both counting modes decreased regardless of particle size. Varying the trigger level of the CNC did not influence the photometric mode counting efficiency. However, the counting efficiency of the single-particle counting mode increased with decreasing trigger level, especially for particles < 20 nm in diameter. Characteristics for individual instruments need to be measured because counting efficiencies of two CNCs with the same trigger level and flow rate were not identical.

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Theory and calibration of a screen-type diffusion battery

Cited by 101 publications

References 8 publications

Size Characterization of Carbonaceous Particles Using a Lovelace Multijet Cascade Impactor / Parallel-Flow Diffusion Battery Serial Sampling Train

Size Characterization of Carbonaceous Particles Using a Lovelace Multijet Cascade Impactor / Parallel-Flow Diffusion Battery Serial Sampling Train

Thoron in indoor air: modeling for a better exposure estimate

Counting Efficiency of the TSI Model 3020 Condensation Nucleus Counter

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