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Total hemispherical emittance measured at high temperatures by the calorimetric method

Conference ·
OSTI ID:10180587
 [1]; ;  [2]; ;  [3]
  1. Case Western Reserve Univ., Cleveland, OH (United States)
  2. Lewis Research Center, Cleveland, OH (United States)
  3. Cleveland State Univ., OH (United States)
A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements ({+-} 5 percent). The probable error of the CVE measurements was typically less than 1 percent.
Research Organization:
National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
Sponsoring Organization:
National Aeronautics and Space Administration, Washington, DC (United States); USDOE, Washington, DC (United States)
DOE Contract Number:
AI03-86SF16310
OSTI ID:
10180587
Report Number(s):
NASA-TM--102322; CONF-890468--15; ON: DE94051204
Country of Publication:
United States
Language:
English