A Miniature Dewpoint Hygrometer for Monitoring Human Environments in Space Microdevices Laboratory/Center for Space Microelectronics Technology/Jet Propulsion Laboratory, California Institute of Technology

Format:

Conference/Event

Author/Creator:

Hoenk, M.E., author.

Conference Name:

International Conference On Environmental Systems (2000-07-10 : Toulouse, France)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2000

Summary:

Water vapor enjoys unique importance in Earth's atmosphere and human environments in space. In spite of this importance, humidity measurement remains a difficult technological problem, and no single instrument is optimal for all applications. We have developed and demonstrated a high-sensitivity dewpoint hygrometer in flight tests on a small radiosonde balloon and the NASA DC8. This instrument achieves fast response to atmospheric humidity by using a surface acoustic wave (SAW) device to detect condensation with much higher sensitivity than conventional optical dew detectors. An early prototype showed more than an order of magnitude faster response than chilled-mirror hygrometers in tropospheric humidity measurements on the NASA DC8. For the radiosonde experiment, we miniaturized and integrated the SAW hygrometer into a 1 kg package that includes pressure and temperature sensors, GPS, a programmable instrument controller, a high-speed radio modem, and lithium-ion batteries. We flew this instrument to 44,000 feet on a small balloon for a side-by- side comparison with a commercial radiosonde. Design elements of the reference radiosonde are presented, along with a discussion of requirements for a hand-held instrument for NASA's Human Exploration and Development of Space Enterprise

Notes:

Vendor supplied data

Publisher Number:

2000-01-2301

Access Restriction:

Restricted for use by site license