NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Laboratory evaluation of an airborne ozone instrument that compensates for altitude/sensitivity effectsOne problem encountered in the use of air-quality instrumentation on aircraft is the variation of instrument sensitivity with pressure as the result of altitude changes of the aircraft. Many instruments experience sensitivity changes of as much as a factor of 2 at altitudes of 6 km. Discussed are recent modifications to a chemiluminescent (ethylene) ozone detector that allow the instrument to automatically compensate for pressure/sensitivity effects. The modification provides automated mass flow rate control for both the sample and ethylene gas flows. The flow control systems maintain flow rate to within 15 percent for a 100-torr instantaneous pressure change, and flow rates are returned to the desired set points within 10 s after the pressure change. During simulated altitude changes (300 m/min from mean sea level to 3-km altitude), flow rates were controlled to within 3 percent of the set point. Laboratory data are summarized verifying the operation of the instrument for a pressure range of 760 torr (sea level) to 350 torr (approximately 20,000 ft) and an ozone concentration range from 20 to approximately 700 ppb.
Document ID
19830064400
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Gregory, G. L.
(NASA Langley Research Center Hampton, VA, United States)
Hudgins, C. H.
(NASA Langley Research Center Hampton, VA, United States)
Edahl, R. A., Jr.
(NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 11, 2013
Publication Date
February 1, 1983
Publication Information
Publication: Environmental Science and Technology
Volume: 17
ISSN: 0013-936X
Subject Category
Aircraft Instrumentation
Accession Number
83A45618
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available