Airborne Cryogenic Frost-Point Hygrometer: User's Guide

摘要

Accurate and reliable low humidity measurements are needed for airborne measurements. The aircraft mounted hygrometer is a very powerful tool for investigating a variety of atmospheric phenomena, especially those which are highly localized or transient in nature. The development of this measurement capability is to eliminate an existing gap in low humidity measurements from an airborne platform by providing fast and accurate frost-point measurements in the -20 to -80 C temperature range. The technical note is a comprehensive report on the performance of the frost-point hygrometer. It should be of interest not only to potential users of this instrument but also to the technical staff as a reference manual for installation, operation, calibration, maintenance and for troubleshooting. The note also documents the evidence on which the Research Aviation Facility at the National Center for Atmospheric Research (NCAR) has decided to consider this device as an operational instrument and to make it available as part of the instrumentation package on the NCAR Sabreliner.