Technical Paper
A Thermal Method for the Determination of Solar Absorptance and Thermal Emittance of Spacecraft Coatings
1993-07-01
932122
For the determination of the solar absorptance αs and the thermal emittance ε preferably optical methods are utilized. To these methods belong spectral reflectance αs and ε measurements and / or emission measurements (only ε), whereby for αs must be measured in the common range 0,3 μm to 2,5 μm and ε in the range 5 μm to 35 μm with an essentially better resolution than 10 nm. Besides so-called integrated reflectance measurements are known, for which special detectors are used, in the above indicated spectral ranges. These optical measuring procedures are relatively exact. They deliver also information about a perhaps spectral selective behavior of surfaces, however, special measuring equipment is required.