|WikiProject Technology||(Rated C-class)|
- 1 Spectrum on page not representative of mercury vapor lamp
- 2 Older discussion (high-pressure vs low-pressure lamps)
- 3 Ultraviolet is your friend!
- 4 How is that
- 5 Picture?
- 6 End of life Section
- 7 Changing the Title of the article
- 8 A new example
- 9 Spam
- 10 Pictures of Lamps
- 11 Metal halide amalgam?
- 12 Kicking off a lamp?
Spectrum on page not representative of mercury vapor lamp
- Whoever added the visible spectrum to the right of the page, please consider replacing it with a (high pressure) mercury vapor spectrum. The spectrum added is that of a triphoshor fluorescent and that is a LOW pressure mercury vapor lamp. Not typical of mercury vapor lamps, which are high pressure.
The spectrum has been replaced to a version with several lines (so probably high pressure), but it still does not correspond to what is expected from the atomic emission spectrum of Mercury. Usually the positions that are given for the Mercury lines are:
- 435.835 nm (blue)
- 546.074 nm (green),
- a pair at 576.959 nm and 579.065 nm (yellow-orange).
(There are two other blue lines at 404.656 nm and 407.781 nm and a weak line at 491.604 nm.) This last part is copied from http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/atspect2.html#c2. FraWa (talk) 11:08, 9 February 2011 (UTC)
- I agree. The very typical green line at 546 nanometer is missing in File:Mercury Vapour Lamp Spectrum.jpg. I will remove it from the article. /Pieter Kuiper (talk) 09:07, 30 September 2011 (UTC)
Older discussion (high-pressure vs low-pressure lamps)
The article states that:
For placements where light pollution is of prime importance (Eg. An observatory parking lot), low pressure sodium is preferred. As it emits light on only one wavelength, it is the easiest to filter out.
low pressure sodium lamps don't emit light of only one wavelength. I can still see red and blue colors in low pressure sodium lamp light. --Abdull 16:39, 30 Mar 2005 (UTC)
- I think you're confusing low-pressure sodium with high-pressure sodium. The light from LPS lamps is, essentially, monochromatic. (It's really two very-closely-spaced wavelengths, but for most practical purposes it's "monochromatic".) The LPS lamp fixtures hold long tubes that look like fluorescent lamps without any phosphor.
- High-pressure sodium lamps, though, while still distinctly yellowish or orangy, are definitely NOT monochromatic. They still have a strong sodium line, but the very high pressure broadens it. Because the filling is actually sodium amalgam, they also have prominent mercury lines and usually neon as well. The HPS sodium lamp fixtures look just like mercury-vapor lamp fixtures.
- It's rather bizarre to stand in an area illuminated solely by LPS sodium light; there really is no color (other than orange) to be perceived. In the USA, you don't find too many pure-LPS sodium light installations, but one is the tunnel on the Wilbur Cross Parkway in Connecticut. You can also find it at the entries to The Big Dig here in Boston, Massachusetts, but it's combined with other lighting so the monochromatic effect is lost.
- Atlant 16:50, 30 Mar 2005 (UTC)
- I'd like to see a discussion concerning the proper disposal of this type of lighting appliance. The mercury it contains frightens the heck out of me.
- ColoradoDoug 12:32, 03 Sep 2007
Ultraviolet is your friend!
The article could use a discussion of the uses of UV generated by Hg lamps, for example in photolithography, microscopy and last but not least, tanning salons! Alison Chaiken 02:03, 3 February 2006 (UTC)
- Alison, this is Wikipedia, so you know what to do: be bold!
- Atlant 13:55, 3 February 2006 (UTC)
How is that
It is written that "The mercury vapor lamp is a negative resistance device and requires auxiliary components (for example, a ballast) to prevent it from taking excessive current". Why does it takes 'excessive current' in the negative resistance regeion. —The preceding unsigned comment was added by 184.108.40.206 (talk • contribs) .
- Have you read the article about negative resistance? But in brief:
- For an ordinary resistance, the resistance of the device doesn't change so current flow through the resistance only rises in proportion to the voltage across the device. If the voltage is limited, so will the current flow be limited.
- For a negative resistance device, though, as more current flows through the device, its resistance decreases. If connected to a fixed voltage source, this reduced resistance allows more current to flow which further reduces the device's resistance which allows more current to flow until... POOF!
- In gas discharge lamps like the mercury vapor lamp, the negative resistance occurs because, as more current flows, there are more current-conducting ions formed in the gas column, decreasing the resistance...
- Atlant 15:44, 9 October 2006 (UTC)
This page needs a picture to show people what these lamps usually look like, and what their color is. If anyone could get that, it would be great. I will also try to get a picture. E.boyer7 22:57, 2 January 2007 (UTC)
End of life Section
In my opinion is wrong: cycling is the end of life behaviour of high pressure sodium lamps.
The cycling is produced by the high voltage ignitor that try to restart the arc in the lamp: traditional mercury vapour lamps have only internal starting electrodes and an external magnetic ballast, they start at mains voltage.
Mercury lamps suffers from blackening of the quartz discharge tube as they age from evaporation of the emitting coating of the electrodes: the lamp never really burns out, it just gets fainter and fainter but is still burning.
After many many years some lamps simply went out because the emitting layer on the tungsten electrodes is totally depleted and the electrode is no longer capable to emit enough electrons to sustain the discharge. —Preceding unsigned comment added by 220.127.116.11 (talk) 01:07, 9 September 2007 (UTC)
Suggest it be made clear (at the End of Life segment) that where these lamps are part of consumer electronics, like an LCD or DLP projector, that they are not "electronic waste" in most regulations in the United States, and should instead be disposed of as "universal waste."
Changing the Title of the article
I think that the heading should be changed to "High pressure Mercury-vapour lamp". Am I wrong or isn't Mercury-vapour lamp sort of general? You could say that a fluorescent lamp is also a sort of Mercury-vapour lamp. DesertDiver (talk) 17:03, 26 February 2008 (UTC)
- Fluorescent tubes require the use of the outer phosphor coating (If I learned correctly), whereas these don't, so a fluorescent tube would be something like a "mercury-excited phosphor lamp" or something. That being said, I think they are nearly universally referred to as "mercury vapors", so we just follow the most common name. 18.104.22.168 (talk) 00:03, 26 April 2008 (UTC)
i agree the title should be changed....and Color Corrected High Pressure Mercury Vapor Lamps do use a Phosphorus Coating. —Preceding unsigned comment added by Edit&Post (talk • contribs) 23:04, 5 May 2009 (UTC)
A new example
Pictures of Lamps
i would like to post Pics that i've taken of These Lamps to show how they look when lit,but i dont know how.(Edit&Post (talk) 18:49, 1 May 2009 (UTC)) —Preceding unsigned comment added by Edit&Post (talk • contribs) 04:10, 1 May 2009 (UTC)
Metal halide amalgam?
The current version has this:
- === Variation: Metal halide ===
- A closely-related lamp design called the metal halide lamp uses various compounds in an amalgam with the mercury. Sodium iodide and Scandium iodide are commonly in use.
According to amalgam, "An amalgam is a substance formed by the reaction of some other substance with mercury." But in that article, every example of an amalgam is with a single element, except ammonium amalgam. Ammonium, like metals, forms compounds as a postive ion. There are no examples offered of amalgams with a compound. But this article implies that there is such a thing as sodium iodide amalgam. I am not a chemist, but I suspect that there is no such a thing as sodium iodide amalgam or scandium iodide amalgam. If I'm right, this section should be rewritten to clarify that it's not sodium iodide amalgam. If I'm wrong, the amalgam article should give an example of a compound amalgam, such as sodium iodide amalgam. Anomalocaris (talk) 07:10, 24 December 2009 (UTC)
Kicking off a lamp?
I don't believe this. I used to work at a steel mill, and we'd installed mercury vapor lamps on a scrap loading crane (the MV lamps ran OK on 250 V DC, though we had to order a bulb with a low enough strike voltage, and of course resistor ballasts)- I'm quite sure those lamps saw a *lot* more vibration than anything even the most energetic hooligan could impart to a street lamp pole, and I don't recall ever seeing them "shaken" out even when the operator of the crane was systematically trying to knock down the building with the magnet. --Wtshymanski (talk) 14:14, 23 February 2010 (UTC) I do beleive this, a few hours ago i kicked the pole of a mercury vapour street light and it went dim then out. 20 minutes later is turned back on as it cooled down. —Preceding unsigned comment added by 22.214.171.124 (talk) 12:37, 21 December 2010 (UTC)