PROCEDURES FOR THE PRECISE DETERMINATION OF THERMAL RADIATION PROPERTIES.
Abstract
A laser-source integrating sphere reflectometer was designed and built to measure the reflectance of specimens at high temperatures. The sphere was calibrated for linearity of response at 0.632 microns by means of a shallow cylindrical cavity with a variable depth-to-radius ratio, having a lining of known reflectance. Preliminary tests showed that the flux emitted by a hot specimen at temperatures up to 2500 K will not invalidate the reflectance measurement. An ellipsoidal mirror reflectometer was calibrated for all known errors in the 1 to 7.5 microns range. A preliminary analysis indicates that the errors in measurement of absolute reflectance with this equipment should not exceed 2%. A review of the literature on relation of thermal radiation properties to other properties of materials is presented, together with a summary of the work done in an effort to compute the spectral emittance of rhodium. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1965
- Accession Number
- AD0478229
Entities
People
- D. P. Dewitt
- J. C. Richmond
- S. T. Dunn
- W. D. Hayes Jr.
Organizations
- National Institute of Standards and Technology