Thermo Optical Parameter Testing

measuring apparatus for thermo-optical parameters
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In space travel, the term "thermo-optical parameters" is used to summarize two optical properties of surfaces whose relationship to each other significantly determines the thermal properties of the surface under space conditions. These two optical properties are the "solar absorptivity (a)" and the "emissivity (e)".

In the measuring apparatus for thermo-optical parameters, the two variables as (spectral solar absorptivity) and eh (hemispherical emissivity) are measured in accordance with the ESA standard ECSS-Q-ST-70-09C "Measurements of thermo-optical properties of thermal control materials". Both measurements are based on the determination of the spectral hemispherical reflectance with the aid of suitable integrating spheres.

Technical parameters

Spectrometer:         Bruker Vertex 80v

spectral range:

  • as-Messung:  250 - 2500 nm
  • eh-Messung       3 – 25 µm

Integration spheres:

  • as-Messung  white-diffuse
  • h-Messung       gold-diffus

Contact

Tom Spröwitz

German Aerospace Center (DLR)
Institute of Space Systems
Mechanics and Thermal Systems
Bremen