Characterization of Humidity Sensors and Physical Properties of H20.

Abstract

Commercially available humidity sensors have been evaluated. There do not appear to have been any significant advances in aluminum oxide devices recently. A new sensor (Thunder Scientific BR-101B) is a little faster than the aluminum oxide types (but not as fast as the manufacturer claims), and it has the significant advantage of a near purely resistive impedance. A monitoring system capable of following fast changes (milliseconds) in sensor parameters has been developed; it detects and records in logarithmic fashion both the magnitude and phase of th sensor's response to a sinusoidal signal. Thermal conductivity of pure ice (Ih) and tetrahydrofuran hydrate has been measured in the temperature range 45 to 200K. The data on the pure ice is in good agreement with previous results. Our data on the clathrate hydrate is a little higher than previous measurements by a radial flow method, but we also find the conductivity to be a factor of 5 (at 200K) to 20 (at 45K) lower than that of pure ice. We find an identical temperature dependence to that found previously, and we extended measurements down to 45K. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1984
Accession Number
ADA139024

Entities

People

  • T. Ashworth

Organizations

  • South Dakota School of Mines and Technology

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Agreements
  • Aluminum
  • Aluminum Oxides
  • Conductivity
  • Flow
  • Humidity
  • Impedance
  • Measurement
  • Monitoring
  • Oxides
  • Physical Properties
  • Radial Flow
  • Thermal Conductivity

Readers

  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Mechanical Engineering/Mechanics of Materials.
  • Sensor Fusion and Tracking Systems.