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Advanced Instrumentation for Water Vapor Measurements from Radiosondes--Yankee Environmental Systems, Inc., 101 Industrial Blvd., Turners Falls, MA 01376-1608; (413) 863-0200
Mr. William M. Stein, Principal Investigator
Ms. Cynthia A. Cote, Business Official
DOE Grant No. DE-FG02-98ER82715
Amount: $750,000
This project will develop a new water vapor sensor suitable for use on balloon-borne radiosondes. The approach corrects several deficiencies found in current balloon-borne water vapor sensors including inadequate accuracy, limited temperature operating range, and slow speed of response at low temperatures. Compared to the current laboratory standard for measuring water vapor content, which uses an optically controlled chilled- mirror hygrometer and costs several thousand dollars, this radiosonde version can be produced for less than $50. The cost reduction is made possible through careful attention to manufacturing costs, modern electronic controls, and manufacturing economies of scale. Phase I evaluated several candidate sensors by chamber controlled testing at humidities and temperatures typically encountered in balloon flights. Balloon flight testing revealed the optical chilled mirror condensation hygrometer to be the only suitable sensor. Phase II will continue the flight testing of two configurations of the chilled mirror hygrometer. One configuration will utilize thermoelectric cooling, and the other will be cooled via cryogenic materials, i.e., dry ice/alcohol slurry. Performance improvements will be sought via improved control strategies, and sample flow ducting.
Commercial Applications and other Benefits as described by he awardee: The atmospheric physicist should be provided with a greatly improved sensor for water vapor measurement. The sensor’s wide dynamic range and fast response make it ideal for radiosonders, as well as other meteorological research platforms. Finally, many industrial processes require monitoring of water vapor in the form of dew/frost or relative humidity, resulting in large number of potential commercial applications.