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Fluorescent Lighting

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Fluorescent Lighting
Posted by Anonymous on Saturday, May 7, 2005 8:09 AM
Fluorescent lights work by producing an electron flow between the electrodes at each end of the tube producing ultraviolet light, which is in turn absorbed by the phosphors coating (substances that emit light when excited by radiation) the tube's inner wall. Those phosphors convert and re-radiate the ultraviolet light as visible light. The mix of phosphors determines the color of the light produced.

Current fluorescent lighting uses standard phosphor blends: cool white, deluxe cool white, warm white, deluxe warm white, white, and daylight. The "cool" phosphors resemble daylight and are more nearly color neutral, while the "warm" phosphors tip the spectrum toward the red end and resemble incandescent lighting. There are also newer bulbs called Full Spectrum that attempt to reproduce daylight more closely but tend to be expensive.

First and foremost to note is that all fluorescent lights produce ultraviolet light. So my concern is the UV light. Even though the amount produced is a lot less than what the sun puts out, over time the UV radiation (3-7 years) produced by fluorescent lights will bleach the color (photochemical degradation) on the layout depending on the amount of exposure and the pigments used in the items - tree and grass material tends to suffer sooner while cars and plastic a bit later.

Buying cheap bulbs and adding filters are a possibility but sleeves can be expensive at $15 to $18 per tube (though there are companies selling 2x4 ceiling covers they're still expensive).

I'm wondering how others might be dealing with this issue. Has anyone run into this? Is it a problem?
  • Member since
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Posted by selector on Saturday, May 7, 2005 1:16 PM
We ran a thread about this subject six or more weeks ago, but the issue was cost. One gentleman favoured the newer Full Spectrums, but the majority tended to prefer the incandenscent approach. The UV problem was not raised, to my recollection, but it is a good point. I wonder if sitting 20" from a CRT while discussing these issues on line ought not to be more of a concern...to the human?

My experience with UV is that it will degrade any organic material, but the first to go is red dye. I can't tell you how many Canadian flags, red t-shirts, plastic flowers, and other items have become severely faded due to solar UV. That said, solar UV must surely be in the order of 20-50 times the strength of that emitted by flourescent bulbs(?).
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Posted by cacole on Saturday, May 7, 2005 3:58 PM
We have fluorescent lights in our clubhouse HO-scale layout room and have noticed no ill effects or color fading despite their being used now for over five years.
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Posted by dinwitty on Saturday, May 7, 2005 9:06 PM
I like flourescents, and there are dimming versions, but very expensive.
I have to figger a way to light my shelf modules because it is closeup lighting.
General room lighting like flourescents or incandesents are out. The multi-level design will not be condusive to broad general lighting.

I will be making a lighting grid of 12 volt lamps with a plastic flat cover that allows light to transfer thru but is not transparent.

Then I may use small low voltage halogens to make a direct sunlight source.
I want to have day/night operations so this will do the trick.


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Posted by bikerraypa on Saturday, May 7, 2005 10:07 PM
ok, here's another question..... Everyone has probably experienced that, when you turn on a fluorescent light while you're listening to the radio, you lose radio reception (particularly AM). Would this have any effect on wireless throttles??

Sorry for a dumb question. I'm just curious.


Ray out
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Posted by rrinker on Saturday, May 7, 2005 10:54 PM
Probably not. It doesn;t seem to impede the corless phone when we take it down to the basement.

But then all our lights are the second tier shop lights from Home Depot - electronic ballasts instead of the old magnetic type you get in the cheapies. No hum from the lights, either.

--Randy

Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by Anonymous on Sunday, May 8, 2005 9:03 PM
Ray,

To answer your question from my experience with my CVP systems wireless, flourescents do not affect wireless reception.

I thought I would add a post I copied a couple of years ago on Flourescent lighting from the Atlas Forum...It covers most of the stuff people are asking about here. It was posted by Rob Vaughn. Hopefully he won't mind the reprint here. It consists of several posts that he made on lighting in a long gone thread. It is very long, but IMHO worth the time.


Well you're in my area now. I spent 15 years as a design engineer for Sylvania Lighting under GTE ownership through their buyout by Siemens which formed today's Osram Sylvania. (Now I engineer automotive engine controls for Toyota--big change)
Anyway, everyone will have a personal opinion on this subject. You could go with standard light fixtures with 100 watt bulbs but you need to evaluate how many you'll need to provide the light level you find acceptable. Depending on your layout size, this can get you in trouble electrically pretty fast. Just remember you can really only get about 16 100 watt bulbs on a standard 15 amp breaker before you run into an issue of overloading it when you flip the switch on. (Remember the post earlier this week on layout fire safety???) Now if your lights are on the same circuit as your wall plugs, take into account everything else you plug in. Hit the button on your drill while buliding benchwork and pop the breaker every time.


Each lamp pulls about 0.909 amps so add them up. Power(P)(Watts)=Voltage(V)*Current(I) I=P/V=100W/110V=.909 amps.
If you have a smaller layout, this is a non-issue but I have a 20 X 40 layout room and would need three 15 amp breakers just for lights.

PAR lamps are an improvement over standard bulbs and will get you whiter light, more of it and save some energy doing it but they do run hot. Most are in the 60 to 90 watt range. Many feel these are too intense and create "hot" lighting spots on the layout that requires standard bulbs to add fill in light adding to your power needs and adding heat to your layout room.

My personal choice is 32 watt flourescent tubes. I installed a drop ceiling using 2X4 panels, bought cheap two-lamp shop light fixtures at Lowes for $8.99 each and then cut 1X4 foot diffuser panels and placed an end to end ring of lights all along the edge of the benchwork. In another words, a standard 2X4 tile panel gets a 1X4 foot tile panel and a 1X4 foot diffuser panel installed. So now you have a continous ring of light all along the edge. Each fixture now pulls about 70 watts of power (lamps plus ballast).

Your next big choice is color. Many people don't understand that lamps come in various colors. A standard shop lamp is a "Cool White" a lamp used in a kitchen is a "Warm White" and offices usually get "Daylight" colors. Lamps are judged on color temperature rated in degrees of Kelvin. The lower a color temp, the redder or "warmer" the color, the higher the temperature, the bluer or "cooler" the lamp appears. Meat counters will always use warm white lamps because they give off redder light and makes all that 3 day old meat look good.

Brightness or light output is measured in "Lumens" and cooler lamps generally output more lumens than warmer lamps meaning a layout lit by warm whites would require more fixtures to get you up to the same "brightness" level as fewer fixtures lamped with cool white tubes. There is now a law that governs what the min lumen per watt output for a lamp is but that is beyond our need for understanding here. It caused many 40 watt tubes to be discontinued and that's all you need in your pocket.

Next is a rating called CRI or color rendering index. This is a rating that judges a lamps ability to reproduce color. The standard is basically equal to color samples viewed under mid-day sunlight outdoors during mid-summer. The closer a lamp gets to making a color sample "look" the same as it "looks" under sunlight, the higher the CRI number. (The samples are 'read" by a spectralradiometer that measures reflected color wavelengths so there is a science behind it)Warm Whites are in the 30-40 range, Cool Whites are generally rated about 40-50 and Daylight lamps get up to the 50-70 range. In our case, the higher the better. Now your standard 100 watt light bulb is in the 25-30 range and down around 27K in color temperature, do your really want to model in these conditions? This is why color matching is so hard and you hear so many people giving Atlas and other manufacturers grief over the colors used. I'm sure Atlas approves color under high CRI lights and Joe Customer takes one look under his 60 watt light bulb in his workshop and has an issue right off the bat. How many prototype locos were ever seen in someone's basement? They are all viewed outdoors under nice bright sunlight............

That's a quick science lesson. What do you want? When I built my layout, I had the advantage of being able to mix my own phosphor coating and custom design my lamps at the big Sylvania plant in Kentucky. I made 32 watt "Supersaver" lamps for energy savings. (These use Krypton gas as a fill vs Argon gas used in a standard 40 watt tube). I turned our $200,000 spectrascan equipment at blue sky in October and read a color temperature of about 67K so my lamps are blended to get 67K output (Off the shelf Daylights are rated at about 55K) And then I went to work getting the CRI up to 95 by using all the best Japan-supplied phosphors. My layout uses 48 lamps so I made up a batch of 400, ran them all through photometric test to ensure they were all the same and now have enough to last me through old age. BTW, I did this all on my own time on weekends and paid for the lamps through our company store so I could get them out the door.

Most people walk into my layout room and say "***!". It's the brightest basement they've ever been in. That's what I did, what can you do???

1) Use low wattage tubes in two lamp fixtures.
2) Make a ring of light around your layout.

3) Check your electrical load and add circuits as needed.
(My lamps run on two isolated breakers--they service no outlets)

4) Invest in several sets of two tubes of different colors. Start by buying two daylight tubes and look at how they reproduce color in your train room. Buy two cool whites and compare. Buy two Warm Whites and compare. (You can get these for less than $2.00 each so make the investment.) Next, bring in a table lamp with a 100 watt bulb and take a look. Make sure there are no other light sources on when you run your little test. The CWs will make your trains look like &^%%^ you can bank on it.

5) Check at Lowes or go to Sylvania's web site and get pricing on lamps called D865 or D965 Designer Series. You'll pay more but they will give you the best representation of sunlight money can buy on our model RR budgets. They are mot cheap but these are what big department stores use and its the reason all those Polo shirts look so darn tempting. It's also why they don't look so good when you get home and look in the mirror. The D865 will get you 65K lamps with a CRI of 82-85 and the D965s will get you 65K lamps with a CRI of 88 to 91. The best you can get. GE offers similar lamps, just make sure you check the ratings.

Lastly, is the old fading issue. UV fades color without a doubt. You can buy UVA and UVB specialty lamps and either tan your butt or fade and age models. Regular lamps use a blend of glass that filters out most of the UV but some does escape and will add to fading of certain paint pigments over time. You have two choices.

1) Buy UV filter covers that slide over the tubes to filter any remaining UV--hard to find but they are out there

2) Go to an automotive store or Lowes and but UV filter film. This is a clear film applied to windows to filter out the sun's UV and it works great in the basement too. Just use it on the inside surface of those diffuser panels I told you to use and the problem is solved. One roll will do all of your basement panels and goes on with a water spray bottle and a sponge.

No UV, no fade, bright layout room and a close representation of sunlight. What could be better?

And one last point, you can buy electronic dimmers for these lamps or buy electronic ballast and dim on a regular dimmer circuit. Expensive but it can be done. I simply have my lamps on three wall switches which controls different "zones" in the room. For "evening" running, I flip on one switch and only about 1/5 of the lamps are on reducing overall illumination. Just a thought.

My $0.02.
Robby Vaughn


My questions to Robby are:
1) What is your general opinion of CFLs and these TCP lamps specifically?
2) Should I stay with the 51k color temperature or maybe go down to 41k (your custom lamps were even "bluer" at 67k) or up to 65k temparture for my layout?
Thanks,
-John


My view on CFLs is that they are great. They have come a very long way over the past few years. They are a perfect sub for incandescents for people who already have the screw-in sockets in place and can drop your current use drastically. A standard 15 amp circuit will support twenty 75 watt incandescents or 75 20-watt CFLs. That's alot of light output! If you do wi***o go the route of CFLs, I highly recommend using the screw-in type vs the ones that mount in a reflector-type fixture. The screw-ins operate on an electronic ballast that ups the operating frequency to eliminate the flicker and supports end-of-life protection.

The first CFLs on the market used a standard magnetic ballast and had a nasty habit of burning up in a violent manner when they decided they had burned long enough. All fluorescent lamps have emissive material bonded to their tungsten filaments. When heated (you apply current) the filaments get hot, and the emissive coating emits electrons that form a plasma arc inside the tube. These electrons hit mercury atoms and cause them to emit UV radiation. The phospor coating absorbs the UV and in turn emits visible light. When a 4-foot lamps runs out of the emitter while operating, the arc attaches to the coil and burns it up making the end of the lamp black. Normally the lamp will flicker and die with no ill effects. CFL are much different since the tube diameter is much smaller. The plasma arc is compressed and runs with a higher power density and much higher operating temperature (thus the higher effeciency). If you doubt this, try touching one that's been on for a few minutes, you'll never do it again. Trouble is, the power density is so high that when the emissive material is used up, the arc attached to the coil, burns it up and then moves to the wire that passes through the glass and proceeds to melt it. Basically the arc runs away and is out of control, something we call half wave rectification. What happens is the arc will follow the wire down into the glass seal and burn a hole through. You would either get a loud "POP", melt down your socket or the tubes would shatter and drop out of their fixtures onto things below. UL finally mandated the use of fusable links in the ballast that would blow when the current shot sky high as the lamps were dieing. The electronic ballast has end-of-life protection built into it in the form of a current limiting circuit that has proven to be pretty failsafe. I pulled all the old magnet ballast styles out of my house years ago but now have some of the new electronic style lamps in my home office and love 'em.

As for TCP, I would bet these lamps are manufactured by Philips and sold to TCP for resale. The equipment to make these is very expensive, especially the twisted type and few startup companies have the millions of dollars to invest in this type of production line. (I think we had something like $15 million invested in one our first Compact lines) Philips has been doing the twisted style for years and may actually hold a patent on it if memory serves.

The color of lamp you use is totally personal choice. I noticed these 27K versions have a CRI of 82 which is darn good for a lamp that "warm". You can bet these have massive amounts of green phosphor mixed in to get the rating up in the 80's. You can't see it with your eye but the frequency of green light is weighted heavy in the CRI calculations and that is a quick fix to meet a rating. Trouble is, the green light is there contributing and reacting with the pigment in your subjects so be careful of low (K rating) temperature lamps boasting a high CRI. Certain colors can start to look odd.

Again, I recommend buying one of each color and viewing your favorite models in a darkened room with the lamp as the only illumination source. Face it, its a lot cheaper to buy four different colors and chuck the three you don't like vs buying 45 and then deciding your Rock Island Blue looks more like BN green. Use the ones you don't like in a table lamp in the bedroom or out in the garage. Personally I like the higher K rated lamps. My reasons for going with the 67K custom blend is that October in Appalachia is my favorite time of year to railfan and I feel I get my best shots under clear blue Fall skies with all the vivid tree colors in the background. I actually waited months to use our equipment to read the October sky and had cheap cool whites in the layout room while building benchwork. IMHO, my efforts were worth it for me, one flick of the switch after installing the 67Ks and I knew I had not wasted my time. Now if you model western roads where the hot summer sun brings out the redder colors of the soils, lower K lamps may make you happy.
Hope this helped somewhat..............
Robby Vaughn


Funny thing about Durotest is that they don't really manufacture most of their products. They are actually made by Osram Sylvania on the very same production lines using the same materials as standard Sylvania lamps. All we would change is the etch which was the little ink pad that applies the "label" to the lamps and the box they ship in. We would run a 2 minute gap to allow the packaging and etch pad to be swapped and start right back up. I've approved Vitalite color samples too many times in the past to count. We also ran many, many GE lamps over the years when they had capacity issues. Was always funny to see us making our main competitor's products for them but it was all about the money. They paid and we made. Someplace I have our old color crossreference guides. Basically, Sylvania supplied most speciality lamps to OEMs like contractors and big chains and then sold the re-labeled or re-branded lamps to companies such as Durotest for low volume sale to the general public. This due to the profits being in high volume sales. That's why it's hard to find a Sylvania lamp in a Kmart or Walmart. GE liked to serve that market.

My point, if you can get the Sylvania lamps cheaper from a distribution source or from the web site, do it. You'll save money and they are the very same lamp you'll pay more for with a different label on them. Basically I have no further ties to Sylvania and don't care what brand you buy, but why pay more. Invest those extra dollars in the next Atlas locomotive release. (Please make in a C-420).
Robby Vaughntop

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Posted by Anonymous on Monday, May 9, 2005 9:26 AM
This is great info Guy. You gave me more than I needed. Rob's take on the on the CRI is a bit different than my own, for me that's a nice change since it will cause me to re-think my own prejudices on the subject. [:D]

Note he says UV is there and that it will [^] fade items (to which I agree). I tested this theory over a short period ~6 months with three identical cabooses. All were vibrant red one sat in my south facing sunroom, one at work under fluorescent lights, and the last remained in the box. After six months the one in my sunroom had faded dramatically, the one from work subtly, and of course the one in the box was pristine red.

I'll have to look around for the UV film he mentioned.

Thanks

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Posted by Seamonster on Monday, May 9, 2005 4:47 PM
Best information I've ever seen on flourescents! Thanks for reprinting it. I've printed it out for future reference. I'm just in the process of changing some of the lights in the house to compact flourescents, so I especially appreciated that info.

I remember years ago many of the employees where I used to work were complaining of the stark bright lighting of the ceiling fixtures, so management changed the tubes in some of them, the ones nearest the desks and work stations, to tubes that gave off a distinctly yellowish-orange light. Much easier on the eyes, and the end of the complaints. The only thing I could find out about them from the maintenance guys was that they were very expensive.

..... Bob

Beam me up, Scotty, there's no intelligent life down here. (Captain Kirk)

I reject your reality and substitute my own. (Adam Savage)

Resistance is not futile--it is voltage divided by current.

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