The Role of Emittance in Refractory Metal Coating Performance. Part III. Total and Spectral Emittance Measurements above 2500 F and Correlation of Emittance with Composition.

摘要

Equipment based upon the sliding specimen principle of emittance measurement is described for measuring total normal and spectral normal emittance to 3000F at air pressures from 0.01to 760mm of Hg. The development of a blackbody furnace especially intended for measuring emittance properties of coated refractory metals is reviewed. The furnace embodies a beryllium oxide tube,special platinum diaphragm seals,and tantalum resistance heating elements. A mathematical analysis of the furnace cavity to establish optimum geometry for blackbody performance is presented which consists of a radiosity network containing 15variables solved with a computer program. (Author)