European Facility For Airborne Research

European Facility For Airborne Research Dec. 4, 2022, 12:38


Title Dual-channel photoacoustic hygrometer for airborne measurements: background, calibration, laboratory and in-flight intercomparison tests
Type Publication

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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GERBIG Christoph
ROLF Christian
SMIT Herman
SZABO Gergely
N. Spelten, M. Krämer, A. Filges
Journal Atmospheric Measurements Techniques
Volume 8
Pages 33-42
Year 2015
Times cited 3
Institute country Hungary
Type of science
  • Atmospheric dynamics (includes thermodynamics)
Field of science
  • Instrument development (includes certification)
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Added Aug. 17, 2017, 11:43
Last update Aug. 17, 2017, 13:10
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File name amt-8-33-2015.pdf
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