Total Hemispherical Emissivity of Sapphire
- 1 April 1965
- journal article
- Published by Optica Publishing Group in Journal of the Optical Society of America
- Vol. 55 (4) , 432-435
- https://doi.org/10.1364/josa.55.000432
Abstract
A calorimetric method is described which has been used to measure the total hemispherical emissivity of crystal-oriented sapphire. The results of two series of measurements are presented, one with the crystal C axis parallel to the surface normal (0° orientation) and the other with the C axis perpendicular to the normal (90° orientation). In the temperature range of −65° to 100°C the emissivities vary from 0.496 to 0.567 for the 0°-oriented sapphire and from 0.471 to 0.552 for the 90°-oriented material. Error analysis indicates that these results should be accurate to better than ±3%.Keywords
This publication has 3 references indexed in Scilit:
- The Reflection and Transmission of Infrared Materials: I, Spectra from 2 50 MicronsApplied Optics, 1963
- Thermal Radiation from Partially Transparent Reflecting BodiesJournal of the Optical Society of America, 1950
- Notes on some radiation heat transfer formulaeProceedings of the Physical Society, 1928