[PT032ABT1], Technical Note, Thomas Alva Edison, March 2nd, 1889
https://edisondigital.rutgers.edu/document/PT032ABT1
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Title
[PT032ABT1], Technical Note, Thomas Alva Edison, March 2nd, 1889
Editor's Notes
The object of this invention is to prevent excessive diminution of Candlepower in Incandescent Lamps.##The invention consists in exhausting the lamps in the regular & well known nmanner but before they are read on the photometer & got ready for shipment they are brought to a Red heat for about an hour in a hot chamber or surrounded by a metallic case so the temperature of the glass chamber will rise far above the termperature of the atmosphere. It is not essential that the filiments should be heated as baking the Lamps at a temperature about 500 for half an hour will answer nearly as well. The effect of the heating the glass chamber after sealing is to drive the air from the gtlobe or decompose such mater as may be condensed thereon The gaseous portion of such matter is driven permanently into the Vacuum's Space & remains The cuase of this phenomenon is not yet understood but the result is that the Candlepower of lamps so heated after sealing is that the fall of CP over any period is roundly 10 per cent less than if not so treated.
Author
Mentioned
Date
1889-03-02
Type
Subject
Folder/Volume ID
PT032ABT-F
Microfilm ID
114:644
Document ID
PT032ABT1
Publisher
Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University