Talk:Fluorescent lamp

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[edit] Kino Flos and the film industry

I'm a little concerned that the mention of kinoflo's (certainly excellent) product is unsupported and seems a little eager to promote the company. There is nothing terribly special about the Kino ballasts or the tubes. The ballasts are a fairly conventional HF design operating between 50 and 150KHz (depending on the exact model and recency) and the tubes, though they have coatings made specifically for them, are no better than many commercial examples of high CRI types. People homebrew fluorescent light fittings all the time and shoot both video and motion picture film on them without any trouble at all.

I'm not in a position to provide properly referenced alternative material, but someone should look at this when they have a moment.

[edit] Efficiency

Should have more about the efficiency, like Compact fluorescent light bulb has.

Also mention the flicker annoying some people, and how it is reduced in some by upping the frequency? - Omegatron 02:35, May 28, 2005 (UTC)

Are the 2 sentences I added including "... Dr. J. Veitch ..." sufficient detail on flicker? I agree that efficiency info would be good, but I'd prefer a big table in Lighting that listed efficiency for every kind all in one place. --DavidCary 23:56, 30 September 2005 (UTC)

[edit] Color Rendering Index and tomato juice

One substance that changes its apparent color dramatically under many fluirescent lamps is tomato juice. Being bright red normally, it turns then to an unpleasant brick-brown. — Monedula 10:30, 30 May 2005 (UTC)

just depends what type of fl tube you use

Tabby 01:53, 3 February 2007 (UTC)

Some other liquids (beer being one example) emit a sickly and almost radioactive green colour when exposed to some frequencies of light from fluorescent lamps, particularly those from black lights.

many organic molecules fluoresce

Tabby 01:53, 3 February 2007 (UTC)

[edit] Efficiency?

Efficiency definitely needs some substance, with some numbers....

7/24/06 There must be some data somewhere about how much energy it takes to manufacture a fluorescent bulb vs. an incandescent. Also on the environmental impact of the materials used in each. My hunch is fluorescent bulbs take a lot more energy to make and are more environmentally hazardous. The longer life of the fluorescent bulb is a mitigating factor, but by how much?

This is important because the people that are trying to shame us into switching to fluorescent are only telling us we'll use less electricity to run them, and nothing about how they're made.

Not to mention the proposed California Assembly bill (AB 722) with the intent of outlawing the sale of all incandescent lightbulbs between 25 and 150 watts in the entire state. I'm fine with fluorescent bulbs in many situations, but they don't always cut it - bathrooms, for example. If the law passes, I guess I'll be ordering my lightbulbs from out of state. ZZYZX 07:42, 8 March 2007 (UTC)

[edit] Make "fluorescent fun" more encyclopaedic

"Fluorescent fun" ... "Alternatively, if you happen to have a Tesla coil handy, you can ..." Somehow this whole chapter doesn't strike me as very encyclopaedic. The same content could be included in the article, but under a better title than "Fluorescent fun" and written in a more matter-of-fact manner. -- 130.233.26.180 06:40, 18 Jun 2005 (UTC)

Is it even healthy to do these things? Accidents happen you know. Especially if you're standing under a high-voltage line... or messing with a Tesla coil. ::: ---

  • I vote for removing the section entirely. --OGoncho 00:03, 16 May 2006 (UTC)
  • I like the section. It may need rephrasing for formality but removing it would be rash.--Deglr6328 00:31, 16 May 2006 (UTC)
  • Keep -- Even in an encyclopaedia, we're allowed the occasional light moment, and what better place than an article about fluorescent lights? Atlant 15:34, 16 May 2006 (UTC)
  • Keep -- As I was reading it, I thought, "This isn't very encyclopedic," but really it's fun and does no harm, and scientific to boot. Trappleton 01:19, 6 October 2006 (UTC)
  • Keep -- This material is useful in explaining how fluorescents work, even if people don't do the experiments.
  • Keep - this is even on my Kid's Encyclopedia :-) --Jollyroger 11:23, 7 December 2006 (UTC)

[edit] How to do the "Fluorescent fun"?

If you live in a dry cold climate with lots of static electricity, try this: Put on your best static-gathering socks and take hold of a short fluorescent tube.

Sounds interesting. but take hold where? Touch to surface where?

Well, the electrodes (pins) are always a good bet (it is unplugged from the fixture, right?), but if you have enough charge on your body, you can touch it almost anywhere and provoke some light. You may even get the light to follow your finger around as you move along the glass tube (envelope). You can do the same think with a TV CRT, by the way. After it's switched off, swirling your finger around on the dark screen (in a very dark room) will often provoke a "comet trail" that follows your finger. Of course, your finger will get dirty from all the dust attracted by the static charges on the faceplate of the CRT. ;-)
Atlant 17:32, 9 February 2006 (UTC)

[edit] Organization

I reorganized the page a bit just now, because the second heading was completely blank. It looked to me that it just needed to have its sub-sections demoted, (which is what I did), but if it was actually blank due to vandalism, could someone fix it? I couldn't see any tons'o'deletion vandalism in recent edits...Stillnotelf 17:48, 1 October 2005 (UTC)

[edit] How much mercury?

Just how much mercury vapour do these things contain? I am wondering since one exploded over me when I was young. Crusadeonilliteracy 13:11, 9 Jan 2004 (UTC)

I hope my recent edit ("about 12 milligrams of mercury" with a link to more details) answers your question. I still wonder -- when the lamp is turned off, does the mercury condense into a liquid, or is there so little mercury in there that it's always mercury vapor? --DavidCary 23:56, 30 September 2005 (UTC)
Mercury weighs a lot, so 12 mg isn't necessarily a lot. I've seen broken fluorescent bulbs in school buildings, and mercury spills in school buildings generally involve evacuation, hazmat teams, the whole shebang. Since we weren't being evacuated, I'd say there's no liquid mercury. Stillnotelf 17:48, 1 October 2005 (UTC)
Whether the mercury is liquid or not depends on the temperature of the fluorescent tube. At operating temperatures, it's usually just about all gaseous, but at low temperatures, it definitely condenses out into droplets; it's this phenomenon that makes it much harder to start and operate a fluorescent lamp at low temperatures (where they often need an insulating sleeve or other enclosure around the lamp to allow them to reach proper operating temperature). You might try experimenting with an ice cube (on a de-energized lamp!).
Regardless, the amount of mercury in a single fluorescent lamp is pretty harmless, but fluorescent tubes become a problem when they enter the waste stream en mass and are landfilled or incinerated. (In the old days, the phosphors were also very toxic, but they're pretty safe nowadays.)
Atlant 14:06, 3 October 2005 (UTC)
You should also includes some examples on all of your descriptions as it is very useful to students

Its unfortunate that data on mercury from coal was removed, incl the graph. Rather it needs developing imho, eg by taking into account the propertion of coal generated power. Tabby 10:19, 23 March 2007 (UTC)

[edit] English dialect

I note the original author lives in Colorado, making him an American. I find "whilst" to be particularly ugly and would support a wholesale change to "while". I believe it's Wikipedia practice to follow the spelling and usage of the original author? --Wtshymanski 03:09, 17 January 2006 (UTC)

[edit] Country variations

Fluorescent lamp control gear designs vary in different countries, due to very different mains voltages requiring different designs, different operating temperature ranges required, different fluorescent tube ranges available, and different customs. Terminology also varies or has different meanings; for example preheat in the US refers to a specific circuit design using an automatic starting switch, whereas in Europe it is a collective term referring to all control gear circuits which attempt to heat the tube filaments before striking the main arc (including but not limited to US preheat circuits).

The section on 'starting' a fluorescent lamp is rather US-centric both in terminology and in the control gear techniques used being more common on 120V mains than 220-240V mains supplies. I started trying to fix it to be more general, but it really needs a restructure or it would become a confusing mess. --Andrew Gabriel--81.187.162.107 21:23, 22 June 2006 (UTC)

[edit] Overdriven fluorescent light

Do you have any information that can help clarify the vague Overdriven fluorescent light article? -- Dogears (talk) 18:45, 31 March 2006 (UTC)

It's nuts.
Don't do it.
Was that enough clarification? :-)
Seriously, this is the reason why "HO" (High-Output) and "VHO" (Very-High-Output) fluorescent lamps exist; they and their ballasts are correctly designed to allow operation at higher drive currents than ordinary lamps and their fixtures are designed with higher operating temperatures in mind. But the idea of paralleling several outputs from a single ballast into a single normal lamp sounds, to me, like a fire waiting to happen; it's akin to taking a table lamp that says "60W maximum", putting a 150W lamp into it, and wondering why the shade starts smoldering.
Atlant 00:42, 1 May 2006 (UTC)

[edit] Fluorescent bulbs and human health

"The cool white fluorescent bulb is legally BANNED in German hospitals and medical facilities." I read this at the Internet. You can find some sources by looking up on google.

I don't speak English very well (I'm Brazilian), but I'm writing in this site because I strongly believe that fluorescent bulbs are very bad for human health, and I believe people in here are interested in researching and finding information about the health hazards fluorescent bulbs may cause in humans. I can't just write this in the article, because I have no scientific source to cite.

The phrase above, about German hospitals, was the closest I could get in my research for some evidence that some government thinks fluorescent bulbs are not good to people. I hope someone in here studies it further, and some reliable fact about health concerns may be put into the article. Wikipedia can be the place to inform people about this important issue.

I believe that many other people around the world dislike fluorescent bulbs as I do. In fact, I think many have come to this article, as I have, looking for some information about all the symptoms fluorescent light may cause. But there is nothing about it on the article! If you look up on the Internet, you will find many websites and blogs with people complaining about fluorescent lights. I believe this information needs to be on this article.

Here are some links I found on a quick Google search on this very important subject:

I believe it would be good, if someone is interested, to research more about this and then write a Wikipedia article about Health Hazards fluorescent lamps cause or to write down a section in this article.

A.Z. 19:22, 30 April 2006 (UTC)

Sadly the claims of "fluorescent light danger" are entirely nonsensical and unfounded in scientific fact and thus will not be added here.--Deglr6328 00:02, 1 May 2006 (UTC)
Well, Deglr6328 is just one voice so doesn't have the last word on this, but you've got to take his point: at the moment, there's very little evidence to suggest that fluorescent lamps are actively harmful to humans, other than the fact that some consider them ugly and they are a minor source of mercury polution when disposed-of. You might make the case that in the absence of any natural light, we suffer Vitamin D deficiencies, but that's not really the fluorescent lamp's fault.
What you might want to do is this: Here on this talk page, compose a brief, cogent summary of why you think fluorescent lighting is bad. We can all collaborate to edit it here, and if the text stands the test, then it will be ready for inclusion in the article. But please be prepared to vigorously defend the points you make, because none of us will accept them lightly or just on your "say so".
By the way, your English is fine; better than mine sometimes, especially when I'm typing!
Atlant 18:45, 1 May 2006 (UTC)

Hi. My dermatologist has just told me that my dermatitis is being aggravated by fluorescent lights at my workplace. I can't find any references to back this up but apparently it is relatively well accepted idea. He said it was the radiation produced rather than the light itself, not sure if he was referring to the UV radiation or to electromagnetic radiation. —The preceding unsigned comment was added by 61.68.171.128 (talk • contribs) .


Wikipedia article on Over-illumination states the following:

"Incorrect spectra (such as fluorescent globes) provide too intense illumination in certain frequency bands compared to other bands. The desired spectrum is that of natural light, which the body is expecting and which is used to set the circadian rhythms of all higher forms of animal life."

"Too great an emphasis upon fluorescent (as opposed to natural) light contribute to incidence of headache.[8]"

"Some studies have shown that the flicker and over-illumination combined in some fluorescent systems yield particularly high fatigue incidence. Research on circadian rhythm in humans indicates that one reason for fatigue stems from the incorrect color spectrum of fluorescent light. For example, the brain of a worker under intense fluorescent light for eight hours perceives itself to have been in total darkness and hence is preparing to sleep under its circadian setting[9]"

"It is clear that brighter, less spectrally correct light induces clinically measurable stress,[10] and it is suggested that for children this over-illumination may interfere with the learning process. For example, in dysgraphia, a defect of learning to write, children experiencing any form of stress are subject to greater incidence of this learning disability. Task performance can also be compromised for people conducting work under artificial (e.g. fluorescent as opposed to natural light)[7]"

"Fluorescent lighting has also been linked to aggravating other psychological disorders such as agoraphobia.[12]"

"Adverse outcomes seem to arise most commonly among workers subject to intense fluorescent light, which is poorly matched to the spectrum of sunlight. According to one set of researchers, the body translates this condition as "total darkness" and resets the circadian clock incorrectly[citation needed]. Not only does this result in fatigue, but also immuno-suppressive behaviour that has been shown to be linked to increased cancers. The research indicates that increasing the ratio of natural light to artificial solves much of the problem, provided the total illumination level is not driven excessively high. Many of these health impacts may be primarily due to the spectrum of the light rather than the overall level of illumination, but more research is required to establish this."

I'd like to know what Deglr6328 has to say about it. What looks clear to me is that we must either take all of those paragraphs out of the Over-illumination article or include these information in the Fluorescent lamp article.A.Z. 22:07, 15 June 2006 (UTC)

I'm not Deglr6328, but that whole article on over-illumination is umm, err, how can one put this politely? "Dubious". I would be opposed to just about anything you find in that article being included here.
Atlant 23:44, 15 June 2006 (UTC)
I would have loved to have given my opinion on that article but sadly my head exploded after reading the very first section. You know that feeling you get when you wish you had never seen a particular wiki article because it is so incredibly bullshit filled yet meticulously cited and researched by someone who has obviously spent a disturbing amount of time thoroughly obsessing over it? This feeling arises mostly because it is clear that any resistance to the pet article or attempts at npoving will be met immediate reversion and will be a futile waste of time and thus one resigns one's self to the fact that wiki can never be perfect and will always contain x% of BS articles. If I were some omnipotent wiki overlord though you can be sure I would delete, delete, delete that article. But I'm not, and I can guarantee that if I were to even touch that article with a 10ft. pole it would likely cause me far more headaches than any supposed "over-illumination" I have ever experienced, so I won't edit it at all. Aside from a single sentence acknowledging the purported phenomenon's existance, there is no WAY I would want the content of that article polluting this VERY good one. --Deglr6328 05:58, 16 June 2006 (UTC)
A single sentence would be a good start. A.Z. 22:05, 28 June 2006 (UTC)
Gee, I thought I was about as clear as politeness would allow, but let me try again: I'm not over there in the Over-illumination article trying to add any actual science to it, but if any of the wild speculation from that article starts appearing in this article, I'll revert it faster than you can say "Suffering pseudoscience!".
Atlant 22:42, 28 June 2006 (UTC)
You should avoid being rude before trying to be funny. A.Z. 18:15, 15 February 2007 (UTC)


"I believe that many other people around the world dislike fluorescent bulbs as I do." (A.Z)

+1

Fluorescent lighting is awful, especially when you are subjected to it for hours upon hours in schools, office buildings, hospitals, and other institutions. Perhaps the reason is psychological, but nevertheless some people strongly dislike this type of lighting. It would be interesting to see this topic developed, but where and how is still unclear. -- Anonymous 72.57.30.206

I'm the furthest thing from a scientist, and as such I don't claim to be able to explain in scientific terms just why I, like so many others, are literally sickened by fluorescent lighting. Perhaps scientists have yet to discover just why fluorescent lighting is so sickning to so many, but I'd hardly call it "pseudoscience" to simply recognize the existence of such a widespread phenomenon. Rather, for a certain "scientist" to so arrogantly dismiss a phenomenon as "pseudoscience" just because s/he can't explain it is to me nothing more than a glaring indication of intellectual insecurity, and ironically, the true makings of a "pseudoscientist". Deglr6328, rather than attack the article as nonsense, why not show some humility and admit that the phenomenon exists, but you just can't explain why? Loomis 03:38, 9 March 2007 (UTC)
I don't really feel the need to formulate a particularly detailed response to someone who obviously hasn't even taken the time to note the actual statements I made in above comments. I never said the phenomenon of people hating fluorescent lighting doesn't exist as I'm sure there are plenty of idle hyperobsessive people who've nothing better to do than complain about such trivialities. This does not of course mean that there is anything harmful or "bad" about fluorescent light. Many people claim to be abducted by aliens who perform anal probes on them, doesn't mean that pheomenon is actually happening, just means that there is a phenomenon where many people THINK its happening. --Deglr6328 06:57, 9 March 2007 (UTC)
I HAVE read your statements. Talk about pseudoscience! You seem to have concluded all on your own that any health concerns regarding fluorescent lighting are just about as credible as claims of alien abduction, diagnosed any and all people claiming to suffer its ill efects as idle hyperobsessives, and concluded that the discomfort they claim to feel, though you've obviously never felt it, is trivial. PLEASE tell me you're not a doctor! If so, what tragic pity I'd have for your patients! "Doc, I'm in terrible pain, can you help me?" "No. I've given you a complete physical and every indication says you're as healthy as a horse. Please quit your whining and get out of my office". Loomis 19:38, 9 March 2007 (UTC)

[edit] Fluorescent tube

What is the meaning of specification "6500 W" written on the tube light?

Oh my! you have a 6500 W?!! That tube is filled with toxic knock-out gas and the phosphor is explosive! get rid of it(carefully)!--Deglr6328 09:17, 29 May 2006 (UTC)

6500K means the colour temperature is 6500K, which is a horribly cold light. Tabby 10:23, 23 March 2007 (UTC)

[edit] Fluorescents: Efficient on short duty cycles?

i have heard that it takes more energy to turn on a fluorescent bulb than a incandescent bulb and therefore it may be less efficient to use a fluorescent bulb in an application where the light is turned on and off frequently. is this true? —The preceding unsigned comment was added by Bwiercinski (talk • contribs) .

Nope, not true. Starting a fluorescent takes very little power compared to the ordinary running power.
Atlant 22:34, 25 June 2006 (UTC)
Agreed. This is an often quoted urban legend. It's difficult to know where it originally came from, as it has never been significant. One possible origin might be that starting a fluorescent tube causes extra wear on the filament emission coating so fluorescent lamps on short duty cycles will typically have shorter lives, although the extent of this depends heavily on the type of control gear used. However, the cost of a replacement fluorescent lamp is normally only a tiny fraction of the cost of electricity it will consume during its life, so unless there are additional high relamping costs (e.g. hire of access towers, etc), worrying about short duty cycles is probably unfounded. I don't know the relative costs of electricity and fluorescent lamps 50 years ago, but maybe this was more of a factor back then?
Andrew Gabriel --81.187.162.107 11:50, 26 June 2006 (UTC)
One possible origin might be that starting a fluorescent tube causes extra wear on the filament emission coating so fluorescent lamps on short duty cycles will typically have shorter lives, although the extent of this depends heavily on the type of control gear used.
I've always assumed that this was the source of the legend.
Atlant 12:30, 26 June 2006 (UTC)

Here is a useful link from the UK's National Energy Foundation, with more Urban Legends, too: http://www.nef.org.uk/energyadvice/lighting.htm

This legend comes from the early days of fluorescent lighting. Starting a magnetic ballast fitting can use anything upto 3x running power for all of a couple of seconds. Somehow this has gotten grossly inflated in popular culture, with many people believing it better to leave a light on for 20 minutes than turn it off! Tabby 10:25, 23 March 2007 (UTC)

[edit] Graphs

I've added an image showing the spectrum for one of the "natural daylight" lamps; if anyone can find a way to work it into the text better, please feel free. Shimgray | talk | 13:57, 11 July 2006 (UTC)

It's excellent. It would also be neat to see a spectrum for an incandescent/halogen light presented in the same section, as a comparison to the fluorescent spectra. ZZYZX 07:50, 8 March 2007 (UTC)

[edit] Dead Fluorescent Still Consuming Power

I recently had an engineer tell me that when a fluorescent lamp dies, it will actually continue to consume power, and its wattage will increase to about 2% more than the nominal wattage. Can anyone confirm this? This is an interesting fact if it is indeed true, and probably should be included in the article, but I wanted to see what you all thought first. Mets 15:16, 27 July 2006 (UTC)

Some do (consume some power), some don't (consume any power); it depends on the auxiliary equipment.
  • A good old preheat lamp with a manual starter and a series inductor for a ballast clearly consumes no power when it's burned out as there's no path for the current to flow, or there'd be light being produced!
  • A preheat lamp with an automatic starter will consume current intermittently with each start attempt. But the current is still limited by the ballast to a value near or less than ordinary running current. And as the article points out, some smarter automatic starters wil "trip out" in this circumstance, stopping the restart attempts until they are manually reset.
  • A rapid-start lamp is, more than likely, still consuming the power required to heat the filaments but is almost certainly consuming less power than a working lamp as there's no arc drawing current.
  • A lamp connected to an electronic ballast depends on how smart the ballast is. Dumb ballasts (such as in most Compact fluorescent lamps) are probably analagous to the rapid-start case above. Smarter ballasts will detect the dead lamp and switch off until mains power is cycled. No electronic ballast can draw a lot more power than normal because they're all fused at a rating not too far above the normal operating current.
Except for cases where the ballast itself is burning up, I can't see any cases where a dead lamp consumes more power than a working lamp.
Atlant 16:06, 27 July 2006 (UTC)

I can think of one case—when the emission coating has gone, and the control gear is operating the lamp in cold cathode mode (as opposed to thermionic emission mode). Ideally this shouldn't happen, but not all control gear will detect the tube voltage increase associated with cold cathode operation and may continue operating the tube. The cathode fall voltage at the cold cathode will increase substantially, generating a lot more heat at the tube end, which is where the excess power ends up. Tubes can't usually operate for long in cold cathode mode before some further failure prevents operation (see main article).

(Andrew Gabriel) 81.187.162.107 21:52, 2 August 2006 (UTC)

Glowstart fittings (US: preheat) will consume well above running power if the _starter_ dies and ends up shorted rather than o/c.

However this is a trivial issue in that it has little overall effect on the energy efficiency of fluorescent lighting. Tabby 10:28, 23 March 2007 (UTC)

Not a trivial issue at all. It has an extreme effect on efficiency of a fluorescent lamp which is not working. A clear disadvantage vs. ordinary incandescent bulbs -- after they break, they do not use any electricity.-69.87.193.242 11:22, 4 April 2007 (UTC)

But the percentage of fl amps not working _and_ using power in the world is tiny, thus it has little effect on the overall efficiency of fluorescent lighting.

Since equivalent filament lighting will have used many times as much electricity for the same number of illumination hours, even one single fl that happens to fail shorted will still have consumed way less electricity in its total lifetime, from initial switch on to final removal. So there is no disadvantage of fls there. Tabby 22:33, 18 May 2007 (UTC)

The lamp itself does consume power, but that is negligible (<.05A). It is the ballast that will continue to consume power. In a magnetic ballast, a non-active lamp will cause the ballast to 'hum' quite loudly. This is less of an issue with electronic ballasts as they are designed to be low-harmonic. JoeIdoni 11:03, 7 Jan 2008

[edit] Start-up power

Is it true that fluorescent lights take loads of power when you switch them on? How much? What is the time period that makes it worth switching off, in order to save electricity? Gwaka Lumpa 18:56, 3 August 2006 (UTC)

It's not true. What is true is that each "start" consumes a little extra life of the lamp; I'm pretty sure the article already mentions this and the mechanism by which it occurs. But the effect is pretty minimal for most practical purposes.
Atlant 19:13, 3 August 2006 (UTC)

I’m sure that turning the power off for a minute or more would save more power then is required to restart a fluorescent light. However, to say that turning the light off and back on uses a little extra of the life of the lamp is an understatement. One mortality life curve I have seen indicates the lamp life went from over 9,000 hours down to just 900 hours when comparing an 8 hour duty cycle to a 3 hour duty cycle. That means you get only 10% of the nominal rated life out of the lamp. Personal experience tells me that shorter duty cycles have an even more drastic reduction in lamp life.

I have some personal experience I can add (here, not to the article) about this. I currently have a fluorescent desk lamp connected to a battery backup for a computer (500VA). The lamp starts more slowly and flickers when running on batteries and the power supply hums until the lamp lights up completely. Neither of these happen when connected to line power. Since the only time the supply hums like that is when it's heavily loaded, I've concluded that starting this particular lamp takes most of the juice the battery backup can provide. Once it's started, it will run for hours, pulling only 20W. Would other fluorescent lamps be different (not require so much startup power)? ZZYZX 08:11, 8 March 2007 (UTC)

[edit] Cleanup

This page needs to be re-organized. It looks like there's a good core article, and then a bunch of added on sections that don't match wiki tone or style, but have additional useful info. --Mcpusc 05:33, 15 September 2006 (UTC)

It's standard Wiki crud-accretion. Please feel freeto be bold and edit the article back into submission.
Atlant 19:15, 15 September 2006 (UTC)
I would, but I have little free time right now. In a couple weeks, if noone else has edited I may come back and fix it. --mcpusc 01:05, 16 September 2006 (UTC)

[edit] Ionisation/plasma?

At any one instant in a domestic fluorescent lamp, what percentage of the mercury atoms are ionised, and what percentage of the inert gas fill is ionised? From the article Plasma (physics), the fact that the fill is gaseous and at least some fo the atoms are ionised does mean that it could possibly be described as a plasma - but reading more deeply, I'm not sure if fluorescent lamps meet the more rigourous definition given later on in the Plasma article. I suppose the follow on from my first question is if the plasma parameter is much, much greater than 1 (That is, is Λ>>1?) for typical fluorescent lamps? WLD 15:52, 20 September 2006 (UTC)

Does this paper answer your question? [1] do you have access to JJAP online? --Deglr6328 22:58, 20 September 2006 (UTC)
Unfortunately, I can't tell - I don't have access to JJAP online. From reading the abstract, I don't think it does. Thanks for the reply, anyway. WLD 07:09, 21 September 2006 (UTC)
Waymouth (“Electric Discharge Lamp” MIT 1971, page 17) have explained that in the mercury noble gas lamp only the mercury atoms are ionized, since the ionization energy of argon atoms is very high (> 13 eV). We have confirmed this explanation by the fast recording of emission spectra (30 spectra were recorded during 3 seconds from the lamp start). The mercury saturated vapor pressure at room temperature is high enough to maintain the avalanche discharge. The role of argon gas is for the plasma temperature stabilization. User PH Duong 10:21 07 Jan 2008 —Preceding unsigned comment added by PH Duong (talk • contribs) 15:23, 7 January 2008 (UTC)

[edit] dimming

There is hardly any coverage of dimming fluorescan's and dosn't mention current technology Back ache 10:55, 15 October 2006 (UTC)

Here's some manufacturer's data; would you like to be bold and update the article?
http://www.advancetransformer.com/uploads/resources/EL-2010-R03.pdf
http://www.advancetransformer.com/uploads/resources/EL-2100-AB-R01.pdf
LonWorks (and maybe BACnet) is also used to provide power-line carrier control of smart (including dimmable) ballasts.
Atlant 23:26, 15 October 2006 (UTC)
JoeIdoni My company typically uses Lutron products for linear dimmable fluorescent. Sylvania, Philips, GE, TCP and several others make compact fluorescent. Additionally the term compact fluorescent can refer to a smaller pin-base lamp which is not self-ballasted. These lamps require a seperate dimming ballast. —Preceding comment was added at 16:07, 7 January 2008 (UTC)

[edit] Practical advice

I think the article should explain how to replace bulbs, how to tell whether the bulb or the charging capacitor needs replacing, and best practice for disposal of bulbs safely. —The preceding unsigned comment was added by Tomhannen (talk • contribs) .

Generally, Wiki isn't to be used as a "how to" reference, but within that general guideline, if you think there's something you can add, please be bold and help us make the article better. I didn't understand what you meant by "charging capacitor", though. Were you referring to the electrical ballast?
Atlant 18:16, 31 October 2006 (UTC)

I guess referring to the starter, which often goes by odd names. A large local outlet here calls them 'starter motors'!

A how to section sounds like a very useful idea to me. Tabby 10:32, 23 March 2007 (UTC)

JoeIdoni Linear fluorescent lamps are connected to the fixture, with little exception, by a socket. This may be a y-shaped, quarter-turn, or push-in type socket. Additionally, there are two variations depending on the lamp and ballast combination. Since a magnetic ballast/T12 lamp and T5 ballast/lamp combinations require 2-wires per lamp end, a non-shunted socket is required. Conversely an electronic/T8 lamp requires only 1 wire per lamp end and will use a shunted socket. An alternate name for the fluorescent socket is a tombstone, referring to it's general resemblances to the namesake. In standard fluorscent fixtures, there is no charging capacitor that can be replaced. If you verify that the lamp is operable, you would replace the ballast. This is not complex, as it usually is a matter of matching wire color, but should not be performed by someone with no electrical experience as the shock from a 120V/277V source can be quite painful, causing injury, severe burns and occasionally death. —Preceding comment was added at 16:14, 7 January 2008 (UTC)

[edit] Broken Reference

Reference 2 leads to a "page not found" type of site. GermanSoccer3 02:44, 12 February 2007 (UTC)

[edit] A couple of questions

An excellent article. A couple of questions and observations if I may.

1. I long ago switched to compact fluorescent lighting throughout the house. Occasionally, I encounter a bulb that starts off dim and takes several minutes to "warm up" to full output. It seems to be a bulb design issue as all five of the CF bulbs in the family room -- purchased at the same time -- do that. I didn't see that directly addressed in the article.

2. At least once, I have encountered a dead fluourescent bulb that somehow prevented any other CF bulb on the same household circuit from starting until it was removed from its socket. Again, I didn't see that addressed.

3. I didn't expect CF bulbs to work all that well in outside motion detector applications, but they do fine. The small sample I've encountered -- three bulbs -- all start reliably down to -20F (-26C) and seem to have normal lifetimes.

4. Purely anecdotal, but my wife has a gooseneck lamp with a high CRI CF bulb in it as part of her portable sewing gear. She loves it, she and her friends feel that it yields better color fidelity than incandescent bulbs.

5. The other night, I flipped off the kitchen light, turned to pick something up, and turned back just in time to see the unpowered bulb reilluminate for several seconds. Disconcerting. Presumably due to something statically charged in the bulb discharging through the gas?

My apologies if these are already addressed and I missed them in my read through of this lengthy article. Again, it's a very good article.

71.169.145.236 12:17, 14 March 2007 (UTC)Donald Kenney

You may want to also see our Compact fluorescent lamp article; it talks about some of the issues (such as slow "warm up") that are specific to CFLs rather than applying to fluorescent lamps in general.
Having said that, your comment (2) is interesting. Other than tripping the branch circuit breaker, I can't see an obvious mechanism that could make that happen for the "dumb" kinds of electronic ballasts used with most CFLs. Meanwhile, I agree with (1) and (3). (4) is definitely true for fluorescent lamps (compact or not) that use the highest-quality (and highest-priced) phosphor mixes. And (5) is a little surprising, but only a little. The electronic ballasts in CFLs use a capacitor to store energy. It's not inconceivable that the rest of the ballast circuitry might glitch on turn-off and dump the last gasps of stored energy into the lamp. Much more common, of course, is that the reddish phosphors used on some lamps continue to glow for a long time after the mercury arc is extinguished.
Atlant 12:43, 14 March 2007 (UTC)

[edit] Flourescent lights eat your brain

I was looking up efficiency information and noticed some odd claims in the introduction that fluorescent lamps were created by the government to eat brains. Another line stated that compact fluorescents do this more so than normal (? If normal could be applied here). I trimmed the lines.

[edit] 2 deletes

"which and affects other equipment which is designed on the assumption that the input alternating current power supply is a clean sinusoidal waveform."

Deleted because

  • no mains equipment is designed with such assumptions.
  • the slight waveform distortion caused by numerous electrical goods, fluorescents included, does not prevent other goods from functioning.

Tabby 10:35, 23 March 2007 (UTC)

Not true. How about electronic transformers? If a leading edge dimmer is used for an electronic transformer designed for a trailing edge dimmer both the dimmer and transformer may be ruined. [2] Even if not ruined, efficiency will be low. Non-switching transformers become less efficient if fed non-sinusoidal waveforms. WLDtalk|edits 17:04, 23 March 2007 (UTC)
  • electronic transformers dont care what waveform they get, all that counts is peak voltage. Theyre as happy on 150v peak square waves as a 110v sinewave.
  • a non-sinusoidal current lighting load has little effect on mains voltage waveform because the mains is a low impedance source. i does not equal v. This makes the issue a non-issue.
  • All mains equipment is designed to cope with the real mains, its imperfections and all.

Tabby 00:26, 24 March 2007 (UTC)


"The frequency is most noticeable on CRT computer monitors set with a refresh rate similar to the frequency of the bulbs, which will appear to flicker due to the beat effect. To resolve this flicker one may change their monitor's refresh rate."

Deleted because

  • this is a significantly different issue to fluorescent light flicker
  • It is a confused explanation
  • It is not caused by and has no impact on fluorescent lighting

Tabby 10:38, 23 March 2007 (UTC)

[edit] Grooved tubes

I thought production of these had long ceased Tabby 10:38, 23 March 2007 (UTC

General Electric still has three "PG17" ("PowerGroove") lamps listed on their website: a Daylight (F96PG17/D), a Cool White (F96PG17/CW), and a Cool White "Watt Miser" (F96PG17/CW/WM). Here's the Daylight lamp:
And some lamp sites still seem to be offering these for sale.
Atlant 11:51, 23 March 2007 (UTC)

Thanks Atlant. Tabby 00:28, 24 March 2007 (UTC)

[edit] Anode / Cathode

Any references to Anode and Cathode are likely to confuse, without great care. AC is used in almost all cases currently; each end takes a turn being Anode or Cathode, many times a second.-69.87.193.242 11:30, 4 April 2007 (UTC)

On the other hand, many fluorescents, especially at the higher power levels, do have distinct "anode" structures adjacent to (and electrically-connected to) the cathode filaments.
Atlant 13:21, 4 April 2007 (UTC)
The electrodes at each end of a tube operate alternately as an anode and a cathode. Much of the electrode structure is designed for operation as a cathode, such as the ability to be externally heated and coating for operation as a thermionic emitter. None of this is required for operation as an anode, where almost any old chunk of conductor would suffice.
81.187.162.109 09:08, 23 September 2007 (UTC) (Andrew Gabriel)

[edit] On Off wearout

"The mix is slowly sputtered off by bombardment with electrons and mercury ions during operation, but a larger amount is sputtered off each time the tube is started with cold cathodes. (The method of starting the lamp and hence the control gear type has a significant impact on this.) Lamps operated for typically less than 3 hours each switch-on will normally run out of the emission mix before other parts of the lamp fail."

So, some types would be very vulnerable to wearout if frequently turned on and off. And presumably some types are not so vulnerable. Please tell us more about exactly which types are least subject to such wearout, and what gives them this capacity. It seems a shame that this important matter is so confusing/confused -- it leaves us having to assume that all fluorescents have this disadvantage, even though only some do.-69.87.193.242 11:39, 4 April 2007 (UTC)

Lamps that pre-heat the cathodes suffer far less damage-at-turn-on than lamps that just use high voltage to blast the arc into existence (so called "instant start" lamps, CCFLs, certain CFLs, etc.). The easiest way to distinguish these is by the number of terminals on the lamp: lamps that have one terminal at each end don't pre-heat the cathodes; lamps that have two terminals at each end usually do preheat the cathodes, depending on the auxilliary equipment that drives them.
The preheat can happen any number of ways:
  • A manual (push-button) switch
  • The "automatic starter" of a traditional pre-heat lamp
  • The continuous filament heater voltage supplied by a "rapid start" ballast
  • The swept-frequency provided by a modern electronic ballast combined with a capacitor that joins the filaments
Atlant 13:28, 4 April 2007 (UTC)

[edit] Efficiency

It would be nice to see more details about the variation in efficiency of normal fluorescents -- a factor of two (from 7% to 15%) is quite a significant range! Exactly why are CFLs only half as efficient as the best non-compacts? What is the possibility of therefore being able to increase the efficiency of CFLs to be comparable? And if the most efficiency fluorescents are 15%, it would be great to see a detailed analysis of the other 85% -- exactly where does it go? The article mentions loss in the phosphor re-emission, which causes heating there -- what is the percentage there? What is the range of loses in various types of ballast? Where else specifically do losses occur?-69.87.193.242 12:13, 4 April 2007 (UTC)

Efficiency is lost in a lot of places. The most obvious, of course, is that "white light" isn't very efficient compared to monochromatic green (555 nm) light (where you can get 683 L/W); see luminous efficacy for details. By comparison, light that we would call "white" tends to top out around 250 L/W or so. The next big loser is the photon conversion loss. Until someone invents the Holy Grail of a "two-photon" phosphor, that 253.7 nm photon has to waste about half its energy getting down-converted to visible light (less waste for conversion to blue but more for conversion to red). Note that this also means that lamps that emit "warmer light" are inherently less efficient than lamps that emit "cooler light" because the warmer-light lamps must produce proportionally more of the less-efficient red light. Cathode loss is probably the next big loser. And for CFLs, a lot of light is wasted in the usual (common) spiral shape of the lamp; light that heads "inwards" in the spiral is noticeably attenuated before it final escapes from the inside of the spiral.
Electronic ballasts can be pretty darned efficient, but there's some energy loss there as well.
Atlant 13:13, 4 April 2007 (UTC)

I love all this detail. Please don't delete any correct information. Likely the cheap transformer type ballasts decrease efficiency a bit, and shorten tube life a bit compared to the best electronic ballasts. The tubes with a blue tint are more efficient, but most people find the light unpleasent, and our eyes respond less to blue light. The flicker affects a few people badly, but most people are affected only by the high brightness, if at all. Low speed flicker = 20 hertz or less is usually because the tube is near the end of it's life. Nearly everyone finds this slower flicker annoying. A bad tube or CFL should not affect other lights, but we should never say never. I cracked the end seal (got too hot) both times I ran a 40 watt florescent at 80 watts plus, but 50 or 60 watts is likely not dangerous, but will reduce tube life expectancy. Many of the 40 watt tubes (near the end of their life only draw about 30 watts from the mains = power company. This is especially true if the input voltage is 105 volts instead of 120 volts. I was plesently surprised when the power company supplied 62 volts rms for about an hour, but more than half of the CFLs were near full brightness. Apparently the low voltage destroyed both ballasts in a set of four 4 foot tube ficture. Is there any good reason cheap tubes of any kind won't light in an induction type fixture for tubes without terminals? I would think some worn out tubes would light that won't in any other kind of fixture. Two out of 20 CFLs = compact fluorescent produced considerable radio noise between 540 and 15,000 kilohertz. Most all fluorescents produce tiny amouts of radio noise = More than incandesant and LEDs. CFLs are slightly less efficient because perhaps 20% of the lighted surface is facing other lighted surface. Much of this mostly hidden light becomes heat. I don't think half is typical. Since the CFLs are newer technology, they are very nearly as efficient and long lived as the cheap 4 foot tubes. Ccpoodle 19:43, 6 October 2007 (UTC)

[edit] PFC

"Fluorescent lamp ballasts have a power factor of less than unity. For large installations, this makes the provision of electrical power more expensive as special measures need to be taken to bring the power factor closer to unity."

I dont see anything special about pfc capacitors, theyre standard kit. Theyre included in most fl fittings, but for large areas eg industry its cheaper to use LPF fittings plus external capacitance.

More expensive than what? Certainly far cheaper than filament lamps. Tabby 07:00, 11 April 2007 (UTC)

The point is that incandescents do not need power factor control, as they are purely resistive loads. Fluorescents require additional components not relevant to light production to achieve a power factor closer to unity. In CFLs, this may be achieved by additional capacitors in the housing, and in standard fluorescents, the choice may be external capacitance. Many CFLs to not have power factor control, and significant increase in their use in residential settings will mean the power supplying utility company will have to do something about it (as well as dealing with separate problems, such as degraded earth/ground due to the use of switch-mode power supplies with their earth leakage currents). WLDtalk|edits 08:02, 11 April 2007 (UTC)

The original paragraph is very simplistic, but covering power factor in conjunction with fluorescents is a non-trivial task. Capacitors can bring power factor back to nearer unity, but cannot completely correct it as the current is not simply phase shifted, and a capacitor can only correct the phase shifted contribution to the low power factor. There's also the issue of 3rd harmonic components of the current distortion, which all add in the neutral of 3-phase supplies (and 6th, 9th, etc harmonics, but they aren't so significant). There are also different control gear circuits which have different power factors. One particularly good control gear circuit which was used in the UK in more expensive luminaries was called SRS -- semi resonant start. This had a power factor of very near 1 without the need for additional correction, and was also very good at starting tubes at low temperatures.
Andrew Gabriel 81.187.162.109 23:46, 12 June 2007 (UTC)

[edit] Heat

With the recent move towards banning incandescents in some countries, could we have some information regarding the differences in heat output compared with fluorescent? Some businesses use incandescents as a heat source, so if a fluorescent doesn't create the same amount of heat that could potentialy be a draw-back that deserves mention. -WarHawk

The power of the lamp equals the heat output, so there isnt really much to tell. Tabby 22:36, 18 May 2007 (UTC)

Simply put: Grab a 100W inc. bulb that's been on for 18 hours with your bare hand. Then grab a fluorescent bulb that's been on the same length of time. One will likely burn your hand, the other will not. JoeIdoni 11:20, 7 Jan 2008

[edit] Graphs

The spectrum graphs of various fluorescent types would be easier to interpret if there was also included graphs of other light types. For example, bright sunlight, cloudy day sunlight, standard incandescent, household halogen - things people would naturally compare the fluorescent light to. 24.17.180.126 17:33, 27 April 2007 (UTC)

[edit] efficiency

Please add a table of the output lumens and lumens per watt for the most common lamps and tubes. Please give data for both the tubes alone and for typical ballast-tube combinations. Please mention addition light losses in the fixture, and give typical percentages. -69.87.201.16 11:52, 25 May 2007 (UTC)

[edit] relamping practices

Industrial and commercial facilities typically use internal fluorescent lighting, on a very large scale. There are many special issues associated with practical aspects of fluorescent tube re-lamping. Typically the fixtures are difficult to access, requiring ladders, disrupting other work etc. So relamping is done often in a very structured way. When a fluorescent bulb burns out, the ballast usually continues to draw power, unlike a burned out incandescent. The fixture may remain in that condition for some weeks or months, wasting power. When fluorescent tubes are all replaced at once, because it is labor efficient, they are prematurely discarded, not giving their maximum potential useful life. -69.87.201.16 11:52, 25 May 2007 (UTC)

[edit] How to tell if flicker is from starter or from the bulb

I wish this article explained how to tell if a flicker is from a bad bulb or a bad starter (or bad ballast). Also, if a lamp with four bulbs is flickering, do you have to replace all four? If not, how do you tell which need to be replaced? r3 21:44, 20 October 2007 (UTC)

There is no way to answer this question. Fluorescent lights are repaired under the assumption that if the lamps are active at all that they are the first to be replaced. If there is no light, the ballast is replaced. Fluorescent lamps and ballasts are so inexpensive at this point that the time put into troubleshooting is over-ridden by the relatively cheap replacement. JoeIdoni (talk) 16:24, 7 January 2008 (UTC)
In a single-lamp, starter-equipped fixture, if the lamp flashes on at all, it's probably not the starter. If the lamp just sits there with its filaments steadily glowing (and no flashing at all), it probably is the starter.
In a multi-lamp fixture, you'll sometimes find that pairs of lamps are operated in some sort of a series circuit; in this case, you may get away with replacing just one lamp, but to me, that seems like just buying another failure soon. Group relamping suggests that if you've reached end-of-life on one lamp, if it wasn't an infancy failure, you'll soon reach end-of-life on the other lamp. If the lamps truly are in individual circuits (like most of my ultra-cheap shoplights), then you can probably get away with changing just one lamp.
Atlant (talk) 16:52, 7 January 2008 (UTC)
Traditional cheap electronic ballasts run two lamps per ballast and are configured so that both lamps go out if one lamp goes bad, usually. Some more expensive high frequency ballasts (Fulham for example) bridge the outputs so the lamps run as if they are individual, but they are not. Both are starterless. Pharmboy (talk) 17:48, 7 January 2008 (UTC)

[edit] Building a lamp that does not burn out?

Has anyone tried building a fluorescent lamp without electrodes? By removing the electrodes and instead making a torus / donut shape, the mercury would form a continuous loop through the glass.

If a portion of this continuous tube were wrapped with a high-density wire coil, and the coil is powered high-voltage / high frequency current, this should be enough to start a current flow in the mercury and light the lamp. (This lamp is essentially an electrical transformer but using the conductive vapor for the secondary circuit.)

Since this would not have thermionic electrodes to sputter out, the lamp life should be extremely long and nearly unlimited (taking into account phosphor aging). Does anything like this exist?

DMahalko (talk) 02:11, 21 March 2008 (UTC)

Have you looked at Electrodeless lamp - more to save energy than lamp cost, bulbs are cheap. Why would I want a lamp that would last longer than I will? --Wtshymanski (talk) 18:04, 21 March 2008 (UTC)
The mercury and disposal issues of compact fluorescents make this type of design worth developing as a consumer illumination device. If lamp disposal only occurs once every 10-20 years, and only due to accidental breakage, that would greatly reduce the volume of mercury entering the environment. The mercury content could increase to assure long lamp life, without the increase contributing to disposal problems. DMahalko (talk) 21:41, 24 March 2008 (UTC)
Just how much mercury comes out of lamps compared to other sources? Not worth anything to reduce 1% down to 0.9%, is it? There are more tons of mercury around in old thermostats than in lamps - and no-one seems at all concerned about the billions of 4-foot tubes practically everywhere. --Wtshymanski (talk) 17:51, 25 March 2008 (UTC)