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| Titel |
Dual-channel photoacoustic hygrometer for airborne measurements: background, calibration, laboratory and in-flight intercomparison tests |
| VerfasserIn |
D. Tátrai, Z. Bozóki, H. Smit, C. Rolf, N. Spelten, M. Krämer, A. Filges, C. Gerbig, G. Gulyás, G. Szabó |
| 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. 1 ; Nr. 8, no. 1 (2015-01-06), S.33-42 |
| Datensatznummer |
250116036
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| Publikation (Nr.) |
 copernicus.org/amt-8-33-2015.pdf |
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| Zusammenfassung |
| This paper describes
a tunable diode laser-based dual-channel photoacoustic (PA) humidity
measuring system primarily designed for aircraft-based environment research.
It is calibrated for total pressure and water vapor (WV) volume mixing ratios
(VMRs) possible during airborne applications. WV VMR is calculated by using
pressure-dependent calibration curves and a cubic spline interpolation
method. Coverage of the entire atmospheric humidity concentration range that
might be encountered during airborne measurements is facilitated by applying
an automated sensitivity mode switching algorithm. The calibrated PA system
was validated through laboratory and airborne intercomparisons, which proved
that the repeatability, the estimated accuracy and the response time of the
system are 0.5 ppmV or 0.5% of the actual reading (whichever value is
the greater), 5% of the actual reading within the VMR range of
1–12 000 ppmV and 2 s, respectively. The upper detection limit of the
system is theoretically about 85 000 ppmV, limited only by condensation of
water vapor on the walls of the 318 K heated PA cells and inlet lines, and
was experimentally verified up to 20 000 ppmV. The unique advantage of the
presented system is its applicability for simultaneous water vapor and total
water volume mixing ratio measurements. |
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