A Proposed Improved Method of Radiosonde Humidity Sensing

Abstract

The carbon humidity element has been used in most U.S. radiosonde flights for the past twenty-five to thirty years. Although it is arguably the best radiosonde humidity sensor in use, the carbon element has physical characteristics that result in significant measurement errors as employed in today's synoptic radiosonde flights. The principal characteristics causing errors are its requirement to be in temperature equilibrium, its poor time response at low temperatures, and its poor sensitivity at low relative humidities. A proposal is made to employ the carbon element in a servo loop designed to control the temperature of the element in such a way as to maintain the measured relative humidity at 33 percent. The temperature of the element will then be used to determine either dew point or the partial pressure due to water vapor. This method will eliminate or significantly reduce the errors arising from the main error source and from some others as well.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Apr 12, 1991
Accession Number
ADA242954

Entities

People

  • James F. Morrissey

Organizations

  • Phillips Laboratory

Tags

Communities of Interest

  • Advanced Electronics
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Air Temperature
  • Dew Point
  • Humidity
  • Instrumentation
  • Low Humidity
  • Low Temperature
  • Measurement
  • Measuring Instruments
  • Meteorology
  • Physical Properties
  • Radiosondes
  • Resistance
  • Sensitivity
  • Standards
  • Surface Temperature
  • Vapors
  • Water Vapor

Readers

  • Climatology
  • Control Systems Engineering.
  • Thermal Physics or Thermal Science.