STANDARDIZATION OF THERMAL EMITTNANE MEASUREMENTS
Abstract
Work was directed toward establishment of equipment and procedures for the evaluation of normal spectral emittance of specimens held at temperatures in the range of approximately 800 to 1400 K (980 to 2060 F), over the wavelength range of 1 to 15 microns. Some of the developments were modified to increase precision and reduce errors in the measurements. One such modification was to provide means whereby a reference blackbody furnace and the hot specimen could be interchanged at will as sources of radiant flux to be measured relative to that from the comprison blackbody furnace. The apparent emittance of the specimen and of the reference blackbody furnace were both measred relative to the comparison blackbody furnace. The apparent emittance of the specimen at each of numerous selected wavelengths was then divided by the corresponding apparent emittance of the reference blakbody furnace to obtain the reported spectral emittance of the specimen. Assembly of the equipment for determination of spectral reflectance, under conditions approximating normal illumintion and hemispherical viewing, was completed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1961
- Accession Number
- AD0259326
Entities
People
- Joseph C. Richmond
- William N. Harrison
Organizations
- National Institute of Standards and Technology