Abstract

Spectral emissivities of platinum for λ=660 mμ have been measured by using an optical pyrometer to compare the brightness of the surface of an incandescent tubular filament with that of a small hole through the wall of the tube. They have been used to compute true temperature as a function of brightness temperature, for the range 1200°K to 1900°K true temperature. The emissivity was found to vary linearly with temperature, from 0.283 at 1200°K to 0.295 at 1900°K. The brightness of an incandescent platinum surface was found to vary with angle of emission rising to a maximum 1.24 times the normal brightness at an emission angle of 80° and decreasing thereafter.

© 1939 Optical Society of America

A New Radiation Pyrometer

John Strong
J. Opt. Soc. Am. 29(12) 520-530 (1939)

A Note on the Color Temperature-Candlepower Characteristic of Tungsten Lamps*

K. S. Weaver and H. E. Hussong
J. Opt. Soc. Am. 29(1) 16-19 (1939)

Thermal Conductivities of Tungsten and Molybdenum at Incandescent Temperatures

Robert H. Osborn
J. Opt. Soc. Am. 31(6) 428-432 (1941)

An Automatic Spectral-Sensitivity Curve Tracer

T. B. Perkins
J. Opt. Soc. Am. 29(6) 226-234 (1939)

Radiation Laws Describing the Emission of Photons by Black Bodies

A. G. Worthing
J. Opt. Soc. Am. 29(2) 97-100 (1939)