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| Titel |
Design and performance of a three-wavelength LED-based total scatter and backscatter integrating nephelometer |
| VerfasserIn |
T. Müller, M. Laborde, G. Kassell, A. Wiedensohler |
| 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 ; 4, no. 6 ; Nr. 4, no. 6 (2011-06-29), S.1291-1303 |
| Datensatznummer |
250002023
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| Publikation (Nr.) |
 copernicus.org/amt-4-1291-2011.pdf |
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| Zusammenfassung |
Integrating nephelometers are instruments that directly measure a value
close to the light scattering coefficient of airborne particles. Different
models of nephelometers have been used for decades for monitoring and
research applications. Now, a series of nephelometers (Ecotech models M9003,
Aurora 1000 and Aurora 3000) with newly designed light sources based on
light emitting diodes are available. This article reports on the design of
these integrating nephelometers and a comparison of the Aurora 3000 to
another commercial instrument (TSI model 3563) that uses an incandescent
lamp. Both instruments are three-wavelength, total and backscatter
integrating nephelometers.
We present a characterization of the new light source design of the Aurora
3000 and provide parameterizations for its angular sensitivity functions.
These parameterizations facilitate to correct for measurement artefacts
using Mie-theory. Furthermore, correction factors are provided as a function
of the Ångström exponent. Comparison measurements against the TSI
3563 with laboratory generated white particles and ambient air are also
shown and discussed. Both instruments agree well within the calibration
uncertainties and detection limit for total scattering with differences less
than 5 %. Differences for backscattering are higher by up to 11 %.
Highest differences were found for the longest wavelengths, where the signal
to noise ratio is lowest. Differences at the blue and green wavelengths are
less than 4 % and 3 %, respectively, for both total and backscattering. |
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