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Metrological validation of the SEALDH-II airborne hygrometer


The SEALDH-II hygrometer is a dTDLAS hygrometer based on first principles, that is capable to monitor its own “health status” with more than 80 control parameters. SEALDH-II has been used in several airborne measurement campaigns on research aircrafts. During a validation campaign over several weeks, SEALDH-II has been compared to a calibrated humidity transfer standard for concentrations ranging from 5 – 1200 µmol/mol (ppm) and under different pressures (65-1000 hPa). As evidenced by this validation, SEALDH-II is the first airborne transfer standard for gas humidity, which, like other instruments of the leading atmospheric research, can be operated under the rough circumstances aboard an aircraft. Results of the completed validation have been published as Buchholz, AMT, 2017, Opens external link in new windowhttps://doi.org/10.519/amt-2016-413.