Talk:Gas-discharge lamp

what about "high-intesity discharge"...?

Do electrons really "circle" an atom??? —Preceding unsigned comment added by 66.176.97.233 (talk) 07:29, 24 July 2008 (UTC)

Incorrect statement

It is stated in the article that HID is regularly used for marijuana growing. This is wrong. High pressure sodium(HPS) lamps and high pressure mercury-vapor are commonly used in cultivating marijuana. The light produced by a High Intensity Discharge lamp is not correct for growing. Article states difference between HPS and HID, this is self defeating later in the article. 70.123.105.146 (talk) 00:54, 28 July 2009 (UTC)

Got a reference that supports the above claim? A Google search on the phrase [ marijuana "high intensity discharge" ] turns up a boatload of pages that appear to refute your claim. 66.53.214.227 (talk) 00:10, 15 November 2009 (UTC)

HID's are usually the ONLY bulbs used by indoor gardeners, due to there ability to replicate the color temperatures of the sun. Metal Halides (5500k-4000k; Blue spectrum) for the vegetative growth of the plant, and High Pressure Sodium (2200k; Red spectrum) for the flowering stage. LED's are increasing in popularity due to no heat being emitted, and a very long life span. But LED's are still the subject of intense discussion in the hydroponic gardening community. Both HPS, and MH bulbs are considered HID's. —Preceding unsigned comment added by 67.82.245.115 (talk) 19:00, 8 January 2010 (UTC)

“The usual metals are sodium and mercury owing to their high vapor pressures that increase efficiency of visible spectrum emission.” Does the high vapor pressure really increase the efficiency of visible spectrum emission? Reference please. Mercury has very little emission in the visible under the best circumstances. Sodium has primary emission in the visible. Isn’t the high vapor pressure more important for uniform high concentration in the gas phase for higher emission efficiency without regard for the spectral region? — Preceding unsigned comment added by Paleotechman (talk • contribs) 20:22, 1 October 2011 (UTC)

Inapropriate to merge

in addtion to that noted above, I also added the neon sign and xenon flash. Leonard G. 03:31, 7 March 2006 (UTC)

-- Just wondering, but are there any examples of gas discharge lamps using water vapour ? That seems pretty unbelievable, and it could be a prank someone had added in. --

Discharge Lamp

Discharge lamp currently redirects to Xenon flash lamp, but Discharge Lamp goes to a stub that sort of points here. It all seems a bit of a mess, unless people think otherwise? Bryson430 13:33, 2 August 2007 (UTC)

If only someone would invent a website where you can type in a phrase and have it search for webpages containing that phrase... You could search on "water vapor" "gas discharge lamp" and find wepages with titles such as " Gas discharge lamp having a water vapor enriched fill -- United States Patent 5394058", and "Journal of Applied Spectroscopy: Emission characteristics of a gas-discharge plasma of water vapor in the vacuum UV region of the spectrum." If someone were to invent such a (to coin a phrase) "search engine" I bet they would make a lot of money. <friendly smile> 75.84.238.18 (talk) 12:14, 15 November 2009 (UTC)

Oppose merge

An arc lamp and a gas discharge lamp are not the same thing and these articles should not be merged. --Wtshymanski (talk) 22:46, 12 September 2009 (UTC)

After our conversation on the arc lamp page I began doing a bit of research. I must also oppose the merge, because there appears to be a definite difference between an electric arc, as found in various types of arc lamps, and an electric glow discharge, which, according to the preliminary research I've done so far, is the mechanism that powers most lights called gas discharge lamps. I'm planning to do some more research, and try to sort this all out in the next few months. I'll probably try to keep the conversation centralized at the arc lamp talk page, if anyone is interested. Zaereth (talk) 20:53, 25 October 2011 (UTC)

Overlapping

The curious reader is going to want to know why we repeat every lamp listed at "high pressure" lamp under "high intensity". --Wtshymanski (talk) 17:01, 22 September 2010 (UTC)

Spectrum

Why has a continuous (thermal) spectrum been included in these illustrations of atomic line spectra ? It seems to me that the entire article is dubious, and of very low quality. — Preceding unsigned comment added by 82.32.48.177 (talk) 10:11, 17 February 2012 (UTC)

That's how it appears when viewed through a prism or diffraction grating. All gases produce spectral lines which are specific to the gas, but they also produce a certain amount of continuum radiation, which is what you see superimposed on the background. How much continuum depends on the types of ion transition that occur, which is tied to current density. Zaereth (talk) 21:56, 3 November 2016 (UTC)

Expansion to include all gas-discharge lamps

I've been looking over this article the last few days, and it seems to me that it should include a brief description of all gas-discharge lamps rather than just the common residential/business lighting (most of which fall into the category of arc lamps). There are also Townsend discharge and glow-discharge lamps (all of which are forms of gas discharges, the main difference being these are much dimmer and operate at a high voltage and current below the runaway threshold, thus do not need a ballast like an arc lamp does). Things like helium/neon lasers or gold-vapor lasers all use gas discharges to produce light. The exception is probably the carbon-arc lamp, in which the arc produces mostly UV light, and the visible light comes from mostly incandescence.

I'm definitely not advocating merging all of these article into one, but rather providing a short description here with "main article" links to their respective articles. That way the reader will have an easy path to the information they are looking for. Plus, this article could use a little more on the plasma physics. Are there any objections? Zaereth (talk) 21:25, 3 November 2016 (UTC)

Doubts about claimed fluorescence in Ruhmkorff lamps

I just copied some info on Ruhmkorff lamps from Heinrich Daniel Ruhmkorff, where it seemed out of place (since H. D. Ruhmkorff apparently wasn't involved in the development of the "Ruhmkorff" lamp). At Talk:Heinrich_Daniel_Ruhmkorff, a user has expressed doubts about the stated mechanism of fluorescence, writing that lower-frequency (red) light usually cannot trigger fluorescence at a higher (green) frequency. I don't know enough about this subject do determine who is right, and the info in the article has a credible-looking source, so I left it in place. OnceAndFutureFlopsy (talk) 13:12, 16 January 2021 (UTC)

The person on the talk page is correct, in that fluorescence is produced when a shorter wavelength is absorbed by a substance and a longer wavelength is emitted from that substance. The difference between the two is called the Stokes shift. The Ruhmkorff lamps were some of the first to really demonstrate spectral lines in gases. In 1864, Professor J. Nickles wrote, "In a vacuum, the electric spark develops light,and that developed by the Ruhmkorff spark takes different colors in different gases; it brilliantly illuminates fluorescent bodies and divides itself into bands separated by dark spaces... ...De la Rive' has reproduced the appearance observed in the Aurora Borealis, justifying, thus, the analogy recognized between the electric light produced in a vacuum and that of the polar auroras."

The analogy here is quite right. Although at low currents CO2 does produce a whitish/pink light, most of its output is in the spectral lines in the far IR, which is invisible to the human eye. However, the carbon does have a very broad and intense line at 389nm (UV, just outside the visual range, but will give you harsh sunburns from a carbon-arc lamp) and a narrow line at 250 nm, and this will surely cause fluorescence. Likewise, while nitrogen can produce a reddish light at very low currents and extremely low pressures, most of its output is concentrated into nitrogen's many spectral lines in the UV, which is also invisible to the naked eye, but will produces strong fluorescence in fluorescent materials. Not to mention at such extremely low pressures and high voltages you will likely be getting wavelengths as short as X-rays (and in fact Ruhmkorff coils were used in some of the early X-ray experiments, until Tesla coils replaced them.) In the 1800s, this nature of gases to produce invisible light was very poorly understood. Fortunately, understanding how something works is not a necessity for exploiting it, or even patenting it. I hope that helps explain. Zaereth (talk) 20:33, 16 January 2021 (UTC)