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| Titel |
Robust, spatially scanning, open-path TDLAS hygrometer using retro-reflective foils for fast tomographic 2-D water vapor concentration field measurements |
| VerfasserIn |
A. Seidel, S. Wagner, A. Dreizler, V. Ebert |
| 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 ; 8, no. 5 ; Nr. 8, no. 5 (2015-05-18), S.2061-2068 |
| Datensatznummer |
250116361
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| Publikation (Nr.) |
 copernicus.org/amt-8-2061-2015.pdf |
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| Zusammenfassung |
We have developed a fast, spatially scanning direct tunable diode laser
absorption spectrometer (dTDLAS) that combines four polygon-mirror based
scanning units with low-cost retro-reflective foils. With this instrument,
tomographic measurements of absolute 2-D water vapor concentration profiles
are possible without any calibration using a reference gas.
A spatial area of 0.8 m × 0.8 m was covered, which allows for application in
soil physics, where greenhouse gas emission from certain soil structures
shall be monitored. The whole concentration field was measured with up to
2.5 Hz. In this paper, we present the setup and spectroscopic performance of
the instrument regarding the influence of the polygon rotation speed and
mode on the absorption signal. Homogeneous H2O distributions were
measured and compared to a single channel, bi-static reference TDLAS
spectrometer for validation of the instrument. Good accuracy and precision
with errors of less than 6% of the absolute concentration and length and
bandwidth normalized detection limits of up to 1.1 ppmv · m (Hz)−0.5 were achieved.
The spectrometer is a robust and easy to set up instrument for tomographic
reconstructions of 2-D-concentration fields that can be considered as a good
basis for future field measurements in environmental research. |
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