🚀 go-pugleaf

In article <28616@cup.portal.com>, mmm@cup.portal.com (Mark Robert Thorson) writes:
> I've been told that the reason for this phenomenon is that the mercury
> condenses in the tube.  If this is true, then it certainly makes sense
> that all tubes -- expensive or cheap -- made for normal household use
> would suffer from the phenomenon.

	This is correct.  The mercury in a fluroescent lamp will always
condense at the coldest point, reducing overall mercury vapor pressure,
thereby reducing light output.
 
	To a lesser extent cold temperatures have an effect upon the
phosphor and inert gas vapor pressure, which not only reduces light
output, but creates color shifts and requires longer starting time.

> It's also reasonable to believe that tubes specifically designed for
> outdoor use would work fine.  Perhaps they have more mercury or lower
> pressure or some mechanism for the filaments to heat the mercury.

	Low temperature fluorescent lamps are generally filled with
argon at lower pressure, in addition to having a thicker or coated
glass wall for thermal insulation.

> Do all flourescent tubes have filaments? 

	No.

> What's the internal difference among 1 vs. 2 pin tubes?

	No filament, and filament, respectively.

<> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp.
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