On Sat 14 Jan 2006 00:48:08, Victor Roberts xxx@lighting-
research.com wrote:

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.


Does this mean that when I smear the bulb of my bedside light with
aromatic oil such as bergamot (to make the smell diffuse into the
room) then I am *noticeably* shortening the life of the bulb?

I'm not worried about a 3% or 4% reduction in life

But a shorter life by 15% or 20% is another thing.