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#844 - 03/21/01 07:45 PM variation in color of fluorescent tubes
Don'tKnowEverythingYet Offline
Member
Registered: 03/18/01
Posts: 22
Loc: Lakewood CA USA
Why is there so much variation of color in fluorescent tubes of one temp, for example 4100k?
Some appear purple, some appear yellow and they're all marked with the same part # and came out of the same box. All ballasts are the same type and the lamps are recommended for that particular ballast.
I don't know what to try next. Has anybody else had this problem?
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#845 - 03/21/01 09:37 PM Re: variation in color of fluorescent tubes
Steve T Offline
Member
Registered: 02/14/01
Posts: 306
Loc: Oak Park, IL, USA
Cheap tubes. Ask for manuf. tolerance levels of different bulbs. Many corporations demand the bulbs are the same color and will not accept them if they vary noticeably.
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#846 - 03/22/01 03:12 AM Re: variation in color of fluorescent tubes
sparky Offline
Member
Registered: 10/18/00
Posts: 5303
high pressure sodium is yellowish, mecury jobs are greenish, metal halide is a tad blue, there's warm white, cool white, all sorts of colors.

doctor's offices want a true skin color, so there is a particular flour. that they like, meat coolers like their meat red looking...

i get the same sort of Q's, drives me nuts


somewhere, there should be a chart as to what visible spectrum is addressed..

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#847 - 03/22/01 10:27 AM Re: variation in color of fluorescent tubes
gto6t7 Offline
Member
Registered: 12/16/00
Posts: 27
Loc: Machias, ME
I just went through this with some lights in a schools biology lab. The answer of cheap lamps is the most probable cause. I used the Granger catalog to help explain the problem. The catalog shows the Color Rendering Index (CRI) and it shows the lamps are rated from 0-100 with 100 being the sun or incandescent lamps. The lamps in the 41k range vari from 62 to 86. Still lamps from the same box should all look the same so its back to the cheap lamps as the cause for your problem.

Dave T.
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#848 - 03/24/01 01:37 AM Re: variation in color of fluorescent tubes
dandy467d Offline
Junior Member
Registered: 12/24/00
Posts: 8
Loc: auburn, ny usa
As with any flourescent or hid lamp, let them run for a few hours they will even out.
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#849 - 03/24/01 08:09 AM Re: variation in color of fluorescent tubes
Don'tKnowEverythingYet Offline
Member
Registered: 03/18/01
Posts: 22
Loc: Lakewood CA USA
Quote:
Originally posted by dandy467d:
As with any flourescent or hid lamp, let them run for a few hours they will even out.


Actually, the problem, believe it or not was mixing different brands. There were GE and Sylvania, both 4100k but still had differences. We went with GE because there were more of them and everybody is happy now.By the way, they didn't come from the same carton as I stated earlier. As we randomly removed each of the ninety fixtures from their cartons, we noticed that some came pre lamped and some didn't. The ones that didn't, got 3500k lamps. That is when the color difference first became apparent.So after three rounds of lamping and re lamping, the nightmare is over and I learned something useful. Thanks for your replies.
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#850 - 03/24/01 11:34 AM Re: variation in color of fluorescent tubes
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Don'tKnow,

I've been following your question and responses. My first impression was they were different Manufacturers. A very common thing that they look different. Thanks for telling us the end of the story so we're not left wondering.


Bill
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#851 - 03/24/01 11:43 AM Re: variation in color of fluorescent tubes
Bill Addiss Offline
Member
Registered: 10/07/00
Posts: 3875
Loc: NY, USA
Here is a Link to some information concerning Fluorescent Lamps, Ballasts, and Fixtures. Nothing specifically on why different brands look different though.
http://www.repairfaq.org/REPAIR/F_flamp.html


Bill
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#852 - 03/28/01 05:36 PM Re: variation in color of fluorescent tubes
Don'tKnowEverythingYet Offline
Member
Registered: 03/18/01
Posts: 22
Loc: Lakewood CA USA
Quote:
Originally posted by Bill Addiss:
Here is a Link to some information concerning Fluorescent Lamps, Ballasts, and Fixtures. Nothing specifically on why different brands look different though.
http://www.repairfaq.org/REPAIR/F_flamp.html


Bill


Thank you for posting this. Lots of good info there. I printed out all 22 pages and put it in a binder.
I have a new adventure now. I only had 30 minutes to check it out so I'll do an update after work tomorrow. There are sixteen 2x4's on two circuits with two sets of 3 way switches. When I turned one breaker off, two fixtures turned off, the rest were mostly off. When I turned the second circuit off, everything was off. Then I turned the first circuit back on and left the second one off and most of the fixtures were mostly off. I turned both breakers on and turned the 3 way switches on and off one at a time and the results were bizarre, unpredictable and not consistent.
Anyway, my mission, should I decide to accept it, is to add six more fixtures. Seems simple enough but this is the same group of criminologists who were unhappy with the different colors.
The new fixtures have electronic ballasts, the existing ones don't.
The whips look longer than six feet and the only one I had time to look at didn't have a ground wire so I'm assuming none of them do. I didn't notice if the flex was steel or aluminum.
This should be lots of fun.
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#853 - 03/29/01 03:08 AM Re: variation in color of fluorescent tubes
sparky Offline
Member
Registered: 10/18/00
Posts: 5303
Thanks for yet another informative link Bill. I shoot much of these to my on-line customers, nothing like an informed one!

dontknow-
post us back on your lighting snafu there...
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