European Facility For Airborne Research

European Facility For Airborne Research May 29, 2022, 09:51

Instrument: M55 Fast In Situ Hygrometer

Name M55 Fast In Situ Hygrometer
Acronym FISH-M55
Manufacturer ICG Juelich
Operated by Geophysica-GEIE
Operated onboard

Instrument type

Name Non dew/frost point hygrometer
Acronym Other hygrometer

Principle of operation

Measured parameter Water Vapour, Relative Humidity
Operating principle

The MOZAIC-Humidity Device (MHD) is a special airborne humidity sensing device (AD-FS2), developed by Aerodata (Braunschweig, Germany) and based on the humidity and temperature transmitter HMP230 of Vaisala (Helsinkin, Finnland). The sensing element itself is a combination of a capacitive relative humidity sensor (Humicap-H, Vaisala) and a Pt100 temperature sensor which has been installed in a Rosemount housing mounted on the outside skin of the aircraft in the vicinity of the nose cone.

Measurement(s) Thermodynamics

Dimension and weight

External dimension
Weight 44.4


Operating mode In situ






Operational restriction

Operational requirements

FISH is calibrated between flights in the laboratory using a calibration bench under realistic conditions, that is varying the H2O mixing ratio of the test air from a few ppmv to several hundred ppmv and the pressure from 1000 to 10 hPa. A frost point hygrometer is used as a reference instrument. The overall accuracy of FISH measurements is 5-6 %.

Certification approvals

Additional information

Water Vapour by Lyman-Alpha
Cornelius Schiller
Tel: 49 2461 615272
Fax: 49-2461-615346
ICG-FZJ Forschungszentrum Juelich GmbHICG-1
(Institut fuer Stratosphaerische Chemie)
Juelich - Germany

Access, host and processing


Could also fit on any aircraft having the following characteristics

General description

Title Author Type Related
No documents.
Back to top
Copyright © 2022 EUFAR All rights reserved.