Luminous efficiency of phosphorus glow

✍ Scribed by E.Q. Adams

• Publisher: Elsevier Science
• Year: 1924
• Tongue: English
• Weight: 73 KB
• Volume: 198
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(24)90023-8

✦ Synopsis

from the radiometer by a water diaphragm and the radiation from the arc after passing through the 8 mm. fused quartz plate and the four sheets of black paper was brought to a focus upon the radiometer vanes by a concave mirror.

The carbon arc in air alone gave small positive deflections. When mercury was added the deflections were nearly as large as those obtained from the mercury arc in quartz, though they were not sufficiently steady for wave-length measurements.

Copper, iron, tungsten, tantalum, and molybdenum gave deflections no greater than the carbon arc alone. Zinc, lead, tin, bismuth, nickel, and calcium gave definitely positive deflections, zinc about onethird that due to mercury and the others less in the order named.

The deflections were evidently determined more by the volatility of the metal and consequently by the quantity of vapor in the arc than by the metal's radiating properties, and were too irregular to permit measurements with the present apparatus.