On Fri, 13 Jan 2006 19:48:08 -0500, Victor Roberts
wrote:


Yes - if the lamp is not properly processed. There is a test
called the "slumper can test" used in the lamp industry to
check for processing contamination. A closed metal can is
placed over an operating incandescent lamp. This heats the
glass to higher than normal operating temperature. If the
lamp is not clean then the higher glass temperature will
drive contaminants such as water vapor out of the glass
bulb, the filament will crack the water into hydrogen and
oxygen and the oxygen will combine with the tungsten,
causing the lamp to have shorter than normal life.

Let me clarify my own statement.

The lamp life will be shorter only if there is contamination
such as oxygen or compounds of oxygen such as water vapor on
the inside glass wall or buried in the glass wall very close
to the inside surface. When the bulb temperature is
increased THIS contamination can be released into the bulb
environment and oxidize the filament.

--
Vic Roberts
http://www.RobertsResearchInc.com
To reply via e-mail:
replace xxx with vdr in the Reply to: address
or use e-mail address listed at the Web site.

This information is provided for educational purposes only.
It may not be used in any publication or posted on any Web
site without written permission.