Mapping the operation of the DMT continuous flow CCN counter. Lance, S., Medina, J., Smith, J., & Nenes, A. Aerosol Science and Technology, 40(4):242-254, 2006.
Mapping the operation of the DMT continuous flow CCN counter [link]Website  doi  abstract   bibtex   
This work thoroughly analyzes a new commercial instrument for measuring Cloud Condensation Nuclei (CCN), the Droplet Measurement Technologies Cylindrical Continuous-Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC). This instrument can measure CCN concentrations at supersaturations from 0.06% to 3% (potentially up to 6%), at a 1 Hz sampling rate that is sufficient for airborne operation. Our analysis employs a fully coupled numerical flow model to simulate the water vapor supersaturation, temperature, velocity profiles and CCN growth in the CFSTGC for its entire range of operation (aerosol sample flow rates 0.25-2.0 L min - 1 , temperature differences 2-15 K and ambient pressures 100-1000 mb). The model was evaluated by comparing simulated instrument responses for calibration aerosol against actual measurements from an existing CCN instrument. The model was used to evaluate the CCN detection efficiency for a wide range of ambient pressures, flow rates, temperature gradients, and droplet growth kinetics. Simulations overestimate the instrument supersaturation when the thermal resistance across the walls of the flow chamber is not considered. We have developed a methodology to determine the thermal resistance and temperature drop across the wetted walls of the flow chamber, by combining simulations and calibration experiments. Finally, we provide parameterizations for determining the thermal resistance, the instrument supersaturation and the optimal detection threshold for the optical particle counter. Copyright © American Association for Aerosol Research.
@article{
 title = {Mapping the operation of the DMT continuous flow CCN counter},
 type = {article},
 year = {2006},
 keywords = {CCN,DMT},
 pages = {242-254},
 volume = {40},
 websites = {http://dx.doi.org/10.1080/02786820500543290},
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 created = {2016-07-07T17:20:28.000Z},
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 last_modified = {2020-11-02T20:28:32.081Z},
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 citation_key = {Lance2006},
 source_type = {Journal Article},
 language = {English},
 notes = {Cited References Count:21|TAYLOR & FRANCIS INC|325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA|ISI Document Delivery No.:017YQ},
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 abstract = {This work thoroughly analyzes a new commercial instrument for measuring Cloud Condensation Nuclei (CCN), the Droplet Measurement Technologies Cylindrical Continuous-Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC). This instrument can measure CCN concentrations at supersaturations from 0.06% to 3% (potentially up to 6%), at a 1 Hz sampling rate that is sufficient for airborne operation. Our analysis employs a fully coupled numerical flow model to simulate the water vapor supersaturation, temperature, velocity profiles and CCN growth in the CFSTGC for its entire range of operation (aerosol sample flow rates 0.25-2.0 L min - 1 , temperature differences 2-15 K and ambient pressures 100-1000 mb). The model was evaluated by comparing simulated instrument responses for calibration aerosol against actual measurements from an existing CCN instrument. The model was used to evaluate the CCN detection efficiency for a wide range of ambient pressures, flow rates, temperature gradients, and droplet growth kinetics. Simulations overestimate the instrument supersaturation when the thermal resistance across the walls of the flow chamber is not considered. We have developed a methodology to determine the thermal resistance and temperature drop across the wetted walls of the flow chamber, by combining simulations and calibration experiments. Finally, we provide parameterizations for determining the thermal resistance, the instrument supersaturation and the optimal detection threshold for the optical particle counter. Copyright © American Association for Aerosol Research.},
 bibtype = {article},
 author = {Lance, S. and Medina, J. and Smith, J. and Nenes, A.},
 doi = {10.1080/02786820500543290},
 journal = {Aerosol Science and Technology},
 number = {4}
}

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