mmm@cup.portal.com (Mark Robert Thorson) (04/06/90)
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. 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. Do all flourescent tubes have filaments? What's the internal difference among 1 vs. 2 pin tubes?
jim@mmsac.UUCP (Jim Lips Earl) (04/06/90)
> Commercial fixtures that take the 8 foot tubes with single pin ends, > work well in the cold. > These are the bulbs used in outdoor lighting. Their prices are > coming down gradually. > I think you can find a two bulb, 8 foot fixture for around $30, > but the florescent tubes run around $8 each. > > I know, it's hard to beat those $9.99, 2 x 48" shoplights, but > you get what you pay for. I hear that! I had to go through three of those junky $9.99, 2 x 48" shoplights before I finally got smart and bought one of those dual 8-foot tube jobbies. It's been working in my garage for over a year now, while those $9.99 things only lasted a couple of months. One of them kept going through tubes, so I bought another. On that one, one of the tubes wouldn't work at all (or was very dim). I'm very happy with my $25 8-foot set. It does "flash" when cold however. But it warms up and stops the flashing in a few minutes. -- Jim "Lips" Earl UUCP: ucbvax!ucdavis!csusac!mmsac!jim KB6KCP INTERNET: mmsac!jim@csusac.csus.edu ======================================================================= The opinions stated herein are all mine.
wolfgang@mgm.mit.edu (Wolfgang Rupprecht) (04/07/90)
In article <29716@amdcad.AMD.COM> phil@pepsi.amd.com () writes: >I'd been having a problem with the lights in my garage not working >too well this winter at night. I just got some information from >the GE Lighting Center and they say some new energy efficient >tubes need to be at least 60 F. Some ballasts have this requirement >too. Phil, why not wrap some nichrome around those bulbs and heat them up? Rumor has it that you can even put a glass jacket around those wires and get light from them directly. ;-) -wolfgang Wolfgang Rupprecht ARPA: wolfgang@mgm.mit.edu (IP 18.82.0.114) TEL: (703) 768-2640 UUCP: mit-eddie!mgm.mit.edu!wolfgang Address: Box 6524, Alexandria, VA 22306-0524
larry@kitty.UUCP (Larry Lippman) (04/07/90)
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. <> UUCP {boulder|decvax|rutgers|watmath}!acsu.buffalo.edu!kitty!larry <> TEL 716/688-1231 || 716/773-1700 {utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 || 716/773-2488 "Have you hugged your cat today?"