Talk:Fluorescent-lamp formats

VHO is used without explanation. Someone knowledgeable should please fix that.

2ft 40W T12, and 5ft 80W T12
I would be interested to know if either of these tube ratings existed outside the UK - I suspect they may be UK-specific. AFAIK, both have become obsolete (in the UK, at least).

2ft 40W was developed specifically for street lighting of minor roads and paths, probably in the later 1940's. It has significantly higher output than the more common 2ft 20W, but not double as it isn't as efficient.

5ft 80W was the first high production volume fluorescent tube size used in the UK in 1939, designed to use the same series ballast as an 80W mercury vapor lamp. Sometime around 1960, 5ft fittings changed to 65W because this was more efficient. However, up until around 1980, 5ft tubes sold in the UK were often dual rated 65/80W, because of the large installed base of 80W fittings.

81.187.162.106 (talk) 09:24, 30 October 2011 (UTC)

CFLs?
Should the various formats for CFL (Compact fluorescent lamp) bulbs be here as well (with a link from the CFL article)? thanks, Facts707 (talk) 05:11, 15 March 2012 (UTC)
 * If you want to retype some manufactuer's catalog, be bold and have at it. We love parts lists on the Wikipedia. They are so easy to type up - "Look Ma, I'm contributing to an encyclopedia!"  But myself, I'd rather have 2 (referenced) paragraphs on *why* there are so many different formats instead of any number of pages out of the Binford catalog. --Wtshymanski (talk) 13:54, 15 March 2012 (UTC)

Article reads like marketing for T5's
The article talks incessantly about T5's, rather than an objective overview of the different formats. This becomes especially prevalent in the later parts of the article. 202.160.48.160 (talk) 06:12, 10 March 2014 (UTC)

Date of first circular tubes?
When were the ring shaped tubes introduced? Bizzybody (talk) 04:43, 9 July 2014 (UTC)


 * They were certainly around by the latter 1950's in Europe, although probably more common in Continental Europe than in the UK. Not sure all countries used same power ratings and sizes. A common setup in the UK was a pendant which used a circular tube in series with an (underrun) 40W mains filament lamp as the ballast. The positive temperature coefficient of the tungsten filament actually made for a very good current regulating ballast and the pendant avoided needing a weighty ballast, although inefficient compared with an inductive ballast. 81.187.1.83 (talk) 12:32, 3 January 2016 (UTC)

Older circulars used inches for the first number and also had a -SW, soft white, designation?
I've got an older GE circular bulb, fc8t9-sw, where the diameter of the circle is 8” and the bulb has 'soft white' printed on it as well the -sw designation. I didn't see inches discussed in the article, and there was no mention of -sw color attribute. Wonder if this is an older format and when it might have changed. Seems like some discussion might be helpful considering they're still in use. Be real, be sober. The WSmart (talk) 16:31, 16 March 2015 (UTC)
 * Looking here, it appears that T9 circlines use inches, while T5 and T6 circlines use centimeters. Ppelleti (talk) 23:10, 17 October 2015 (UTC)
 * “SW” indicates a warm white deluxe halophosphate phosphor. I added “WWX” as a suffix but not “SW”. I might add that some time soon. Fluorescentlover2009 (talk) 13:31, 3 November 2022 (UTC)

Reference for numeric color code table?
Is there a reference for the CRIs listed in the numeric color code table? For example, the table in the article says a 950 code has a 98 CRI, but this link shows a 950 with a CRI of 90. --Ppelleti (talk) 03:49, 6 September 2015 (UTC)


 * The 9 in 950 means the CRI is between 90-99. Similarly, 8xx would mean CRI between 80-89 and 7xx would mean CRI 70-79.
 * The 50 in 950 means a colour temperature of 5000K. Similarly, 830 would mean a colour temperature of 3000K. 81.187.1.83 (talk) 12:37, 3 January 2016 (UTC)

F15T8
A standard size missing from the table seems to be "F15T8" which is acutally 17" long in T8 (~1" diameter) format. The one I have here is labelled F15T8/D and is 17 3/4" including the length of the pins. There is another variant which is 17 7/8" but I'm not sure if its designation; that might be the F15T8/CW but I'm not sure. dhollm (talk)

Reply: I added F15T8 to the common sizes table. The F15T8 is actually 18" nominal and the /D and /CW suffixes actually indicate the phosphor used, not the length. For example, an F15T8/CW would use the halophosphate cool white phosphor while an F15T8/D would be halophosphate daylight. By Fluorescentlover2009, Nov. 2, 2022

Need an explanation of how T8/T12 tube length is coded
Many ballasts specify tube type using a code like FxxT8 or FxxT12 where xx is a number like 15 or 40 (and many others). Presumably the xx number somehow relates to the length of the tube, but there can't be that many different lengths - right? So how is a 48" T12 tube coded? Is it F48T12?  An explanation of how the xx number relates to actual tube length is needed.

Reply to unsigned post above: My understanding is that (a) all tubes of a certain diameter run at the same current, and (b) the length determines the required voltage (post ballast) and hence wattage. A marking of F40T8 says the ballast will run any 40watt T8 tube. Electronic ballasts can be flexible and list several popular tubes they will run. Also a supplier (who knows the real ratings envelope) may be able to help you with less popular tubes not listed on the ballast casing. I cannot cite this info as it was obtained courtesy of such a supplier. Shannock9 (talk) 21:13, 8 September 2019 (UTC)

The article almost answered my question about nomenclature
I'm looking for a circular T5 bulb, outer diameter 7.25 inches.

Would I search for an FC7T5? an FC725T5? an FC7.25T5?

Here is an opportunity to improve the article. Thanks. 2601:281:CC80:5AE0:300E:B1F:FAC9:7CA0 (talk) 14:50, 25 January 2020 (UTC)


 * I searched FC7T5 and some results came up. I think if the diameter Is a decimal it is rounded up. The FC8T9 is the same way. Fluorescentlover2009 (talk) 13:42, 3 November 2022 (UTC)

LEDs
Should this article cover LED tubes and the issues of retrofitting them to fluorescent fittings? Slava Ukraini fellas (talk) 19:39, 7 October 2022 (UTC)
 * No, because this don't related to this article topic. זור987 (talk) 06:27, 8 October 2022 (UTC)
 * So whats a "fluorescent lamp"? A thing with mercury in it?  Or a long thin tube that lights up, same as most people think?   If not this article, then where? Slava Ukraini fellas (talk) 07:56, 8 October 2022 (UTC)
 * A fluorescent lamp is a long tube with low pressure mercury vapor which emits UV that excites the phosphor coating inside it. זור987 (talk) 08:03, 8 October 2022 (UTC)
 * Is a T8 fluorescent?  Because there are now LED T8s. If we don't describe them here, then where? Slava Ukraini fellas (talk) 08:06, 8 October 2022 (UTC)
 * T12, T8. etc, all intended to indicate the thickness of the tube. A LED tube designed to retrofit a fluorescent tube in its lampholder. Fluorescent lamps are exists in T8 as well, for example the European energy saver T8 lamps. זור987 (talk) 08:09, 8 October 2022 (UTC)
 * So if not here, where? Slava Ukraini fellas (talk) 08:10, 8 October 2022 (UTC)
 * OK, I've just read your user page. Clearly you take a very narrow view of content and are only interested in definitions, not article value. I guess you wouldn't be interested in answering this question and don't appreciate that there are other readers who do. Slava Ukraini fellas (talk) 08:13, 8 October 2022 (UTC)

Are North American fluorescent phosphors the same as European ones?
I have noticed in the "colors" section of this article that the European fluorescent phoshpors are listed with different CCT and CRI ratings than those in North America. For example, the standard cool white halophoshate phosphor is listed in the article as being 66CRI and 4300k while they are commonly rated at 62CRI 4200k here. Is this the same phosphor or is it different? Another example is the daylight deluxe halophosphate. The article has them listed as being a whopping 94CRI while the ones I see are only 88-90. Warm white deluxe, in the article it is 85CRI, while here it is quite a bit lower at 77. Are these different deluxe halophosphate phoshors? Fluorescentlover2009 (talk) 22:09, 12 November 2022 (UTC)