The radiation of energy from a thoriated tungsten filament and the absorption of the energy radiated from the surrounding bulb have been measured by a method which eliminates difficulties arising from cooling effects of the leads. For a filament at a uniform temperature TF in a bulb at temperature TB the net radiation W in watts cm−2 is the difference between the outgoing radiation WR and the absorbed radiation WA. For values of TF from 225° to 580°K and TB from 77° to 473°K
The resistivity R0
in this same range is given by
The characteristics, current, voltage, resistance, and energy radiated as functions of temperature are tabulated.
© 1935 Optical Society of America
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