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Titel |
Mobility particle size spectrometers: harmonization of technical standards and data structure to facilitate high quality long-term observations of atmospheric particle number size distributions |
VerfasserIn |
A. Wiedensohler, W. Birmili, A. Nowak, A. Sonntag, K. Weinhold, M. Merkel, B. Wehner, T. Tuch, S. Pfeifer, M. Fiebig, A. M. Fjäraa, E. Asmi, K. Sellegri, R. Depuy, H. Venzac, P. Villani, P. Laj, P. Aalto, J. A. Ogren, E. Swietlicki, P. Williams, P. Roldin, P. Quincey, C. Hüglin, R. Fierz-Schmidhauser, M. Gysel, E. Weingärtner, F. Riccobono, S. Santos, C. Grüning, K. Faloon, D. Beddows, R. Harrison, C. Monahan, S. G. Jennings, C. D. O'Dowd, A. Marinoni, H.-G. Horn, L. Keck, J. Jiang, J. Scheckman, P. H. McMurry, Z. Deng, C. S. Zhao, M. Moerman, B. Henzing, G. Leeuw, G. Löschau, S. Bastian |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1867-1381
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 3 ; Nr. 5, no. 3 (2012-03-29), S.657-685 |
Datensatznummer |
250002637
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Publikation (Nr.) |
copernicus.org/amt-5-657-2012.pdf |
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Zusammenfassung |
Mobility particle size spectrometers often referred to as DMPS (Differential
Mobility Particle Sizers) or SMPS (Scanning Mobility Particle Sizers) have
found a wide range of applications in atmospheric aerosol research. However,
comparability of measurements conducted world-wide is hampered by lack of
generally accepted technical standards and guidelines with respect to the
instrumental set-up, measurement mode, data evaluation as well as quality
control. Technical standards were developed for a minimum requirement of
mobility size spectrometry to perform long-term atmospheric aerosol
measurements. Technical recommendations include continuous monitoring of
flow rates, temperature, pressure, and relative humidity for the sheath and
sample air in the differential mobility analyzer.
We compared commercial and custom-made inversion routines to calculate the
particle number size distributions from the measured electrical mobility
distribution. All inversion routines are comparable within few per cent
uncertainty for a given set of raw data.
Furthermore, this work summarizes the results from several instrument
intercomparison workshops conducted within the European infrastructure
project EUSAAR (European Supersites for Atmospheric Aerosol Research) and
ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure Network)
to determine present uncertainties especially of custom-built mobility
particle size spectrometers. Under controlled laboratory conditions, the
particle number size distributions from 20 to 200 nm determined by mobility
particle size spectrometers of different design are within an uncertainty
range of around ±10% after correcting internal particle losses, while
below and above this size range the discrepancies increased. For particles
larger than 200 nm, the uncertainty range increased to 30%, which could
not be explained. The network reference mobility spectrometers with
identical design agreed within ±4% in the peak particle number
concentration when all settings were done carefully. The consistency of
these reference instruments to the total particle number concentration was
demonstrated to be less than 5%.
Additionally, a new data structure for particle number size distributions
was introduced to store and disseminate the data at EMEP (European
Monitoring and Evaluation Program). This structure contains three levels:
raw data, processed data, and final particle size distributions.
Importantly, we recommend reporting raw measurements including all relevant
instrument parameters as well as a complete documentation on all data
transformation and correction steps. These technical and data structure
standards aim to enhance the quality of long-term size distribution
measurements, their comparability between different networks and sites, and
their transparency and traceability back to raw data. |
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