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%.

© 1965 Optical Society of America

The total hemispherical emissivity of copper

R. Smalley and A. J. Sievers
J. Opt. Soc. Am. 68(11) 1516-1518 (1978)

Total hemispherical emissivity of tungsten

D. P. Verret and K. G. Ramanathan
J. Opt. Soc. Am. 68(9) 1167-1172 (1978)

Total hemispherical emissivity of W(100)

L. A. Wojcik, A. J. Sievers, G. W. Graham, and T. N. Rhodin
J. Opt. Soc. Am. 70(4) 443-450 (1980)

Temperature variation of total hemispherical emissivity of stainless steel AISI 304

C. R. Roger, S. H. Yen, and K. G. Ramanathan
J. Opt. Soc. Am. 69(10) 1384-1390 (1979)

Adsorbate-induced change in the total hemispherical emissivity of W(100)

L. A. Wojcik, A. J. Sievers, G. W. Graham, and T. N. Rhodin
J. Opt. Soc. Am. 72(1) 149-155 (1982)