TOTAL HEMISPHERICAL EMITTANCE AND NORMAL SPECTRAL EMITTANCE (LAMBDA = 0.65 MICRON) OF OXIDATION PROTECTIVE COATINGS.
Rept. for 27 Feb-19 Dec 62,
NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF
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Measurements of the variation of total hemispherical emittance and normal spectral emittance Lambda 0.65 micron with increasing temperatures have been made on some pack-cementation disilicide type oxidation resistant coatings for the refractory metals, molybdenum, tungsten, niobium and tantalum. The normal spectral emittance Lambda 0.65 micron of the coatings on disc samples, was determined with a micro-optical pyrometer, which was sighted into a black body hole, drilled in the sample and then onto the adjacent area. The total hemispherical emittance of the coatings on ribbon specimens was found by use of a calibrated total radiation pyrometer, which sampled the energy radiated from a uniform temperature region established about the center portion of the electrically heated ribbon specimen. The diffuseness of the surface of the various coatings was found by taking angular distributions of the radiation emitted from the center portion of the sample ribbons at various temperatures with the total radiation pyrometer. The confidence limits placed on these data are 15 percent. Author