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Development of Flight Aluminum Oxide Water Vapor Sensor Systems.

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Final rept. 1 May 75-31 Aug 76,

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Stratospheric humidity profiles were obtained with heated Al2O3 type water vapor sensors whose temperature during flight was maintained constant. Additional profiles were obtained with newer, integrated circuit type Aquamax TM sensors. The heated sensor provided frost point data which generally increased with stratospheric altitude, in agreement with most earlier unheated sensor data. It is concluded that this type of humidity profile cannot result from ambient temperature effects upon the sensor. Heated sensor flight requirements resulted in excessively rapid descent rates and are thus incompatible with conventional radiosonde deployment. Aquamax sensors, which exhibit at least an order of magnitude more rapid response time in laboratory test systems, were flown unheated and data were corrected for ambient temperature. Some resultant profile data obtained during a much slower descent were almost identical with the heated sensor data, providing additional evidence that the Al2O3 type sensor has an adequately rapid response time for balloon flights. Other Aquamax sensor profile data indicated a constant mixing ratio stratosphere which is unusual but has been observed earlier for Al2O3 sensor data. Data indicate that stratospheric profiles are variable and may be related to stratospheric circulatory patterns. Aquamax sensors, when developed in a heated version, should provide a means for convenient deployment with conventional radiosondes.

Subject Categories:

  • Meteorology
  • Test Facilities, Equipment and Methods

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