TEMPERATURE VARIATION AND SENSITIVITY IN TWO-PHASE THERMAL IMAGE DETECTORS

Abstract

The feasibility of using an isothermal two-phase system for thermal imaging was examined. This supplement to the final report comprises a mathematical analysis of the operation of such a system, taking into account a temperature difference between the two phases. Through the analysis it is finally shown that the sensitivity and the temperature difference have opposite signs for all imaging films of practical thickness, where the temperature difference is defined as positive when the liquid state is warmer than the solid state; and the sensitivity is defined as positive when the ratio of liquid to solid increases when the received radiation increases. This means that there is no steady-state or stable configuration of the film, under the assumptions of one substance in two phases, subjected to the radiant fluxes assumed in this report, except for films so thick that heat conductance is negligible compared with radiative transfer. (Author)

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1959
Accession Number
AD0287746

Entities

People

  • Conrad Schadt

Organizations

  • SRI International

Tags

DTIC Thesaurus Topics

  • Detectors
  • Images
  • Mathematical Analysis
  • Radiation
  • Radiative Transfer
  • Sensitivity
  • Steady State
  • Thermal Images
  • Thickness

Readers

  • Control Systems Engineering.
  • Thermal Physics or Thermal Science.
  • Thin Film Deposition Science.