Abstract

A 200-ampere 80-volt fully automatic carbon arc lamp is described which is capable of operating uninterruptedly for many hours at a time. The peak brightness of the positive crater is over 1600 candles per square millimeter, its average brightness approximately 1200 candles per mm², with averaged brightness variations of only ±3 percent. The total radiation density of the crater in watts per cm is equal to that of a blackbody of approximately 5400°K, whereas the spectral energy distribution of the visible radiation resembles that of a blackbody of approximately 7000°K. The arc, of 18-mm length, is operated between the rim of a negative graphite disk of 20-cm initial diameter and the positive crater of a water-cooled 11-mm super-high-intensity carbon which is consumed at the rate of approximately 40 inches per hour. Fine air streams protect the water-containing positive metal jaws from flashbacks of the arc. A positive magazine mechanism was developed by which automatically one positive carbon is joined to the next one, thus enabling the arc to operate uninterruptedly. Feeding of the positive carbon and rotation of the negative disk are triggered by the arc itself by means of electric probes. The new lamp may be used wherever a reliable automatic source of very high brightness, high-total radiant emittance, and high temperature is required.

© 1954 Optical Society of America

Modification of the Carbon Arc Searchlight for Producing Experimental Flashburns*

Thomas P. Davis, Leo J. Krolak, Robert M. Blakney, and Herman E. Pearse
J. Opt. Soc. Am. 44(10) 766-769 (1954)

Carbon Arc as a Radiation Standard

M. R. Null and W. W. Lozier
J. Opt. Soc. Am. 52(10) 1156-1162 (1962)

Intensity Measurements in the Arc Spectrum of Nickel

Roland L. Heid and G. H. Dieke
J. Opt. Soc. Am. 44(5) 402-410 (1954)

Relative Intensities of the Raman Lines of Carbon Tetrachloride, Chloroform, and Methylene Chloride

H. J. Marrinan and N. Sheppard
J. Opt. Soc. Am. 44(10) 815-819 (1954)

Carbon Arc in a Controlled Atmosphere as a Radiation Standard*

Robert R. Jayroe and R. G. Fowler
J. Opt. Soc. Am. 57(4) 513-516 (1967)