Difference between Xenon, Krypt... etc...bulbs

Hi All,

I have a very specific question, it always quizzels me...

What is the difference between the the following incand lamp types
1) Xenon
2) Krypton
3) Halogen
4) Normal Lamps...
5) Any More Technologies in incand

What are the brightness levels, Lifetimes, Advantages, Disadvantages, any minimum voltages / currents, Typical applications, CRI, Comparisons & Comparitive Data....

So many doubts.... Is there any web page / link where i can get good information... i did google first before posting here.. but i got really vague results...

Help .... /ubbthreads/images/graemlins/help.gif

Thanks & Regards,
ViReN

Xenon and Krypton are both inert gasses. That allows somewhat higher filament temperatures, and longer life since even at the temperatures of the filament, no chemical reactions take place between the filament and the gas inside the bult envelope. However there is loss of brightness with age, because some of the filament material boils off the filament and deposits itself on the glass, hence the darkend areas on many frosted lamps at end of life, and the darkened ends of fluorsecent tubes.

Halogens are very reactive elements, the main advantage is they also allow higher filament temperatures, but prevent the deposition of material on the glass envelope. Material does boil off, and does deposit on the glass envelope, however it reacts with the halogen (usually Iodine, sometimes bromine), and ends up being removed from the walls and redeposited on the filament. This takes place at fairly high temperatures, so the application has to be designed so the that filament can reach the required temperatures for the reaction to take place. The design also has to limit the envelope temperature to prevent envelope or seal failure. These lamps have to run long enough for the halogen cycle to operate. The halogens generally have the highest Color temperatures and highest efficiencies. CRI for all incandescents is a non issue. CRI is a measurement of how well the spectral output of a lamp approximates a 'black body' at the stated colour temperature. Filaments are for all practical purposes black bodies, so they have CRI's of 100. Lifetime is mostly is mostly related to filament temperature, which is driven by applied voltage. The higher the filament temp, the higher the colour temperature, the higher the luminous efficiency and the shorter the life. Radiated energy goes up at T^4, so even modest increases in color temperature (filament temp) improve the Lumious efficiency. The higher temperatures also speed up the filament evaporation and deposition on the envelope, so brighness is lost unless you can remove the deposits (which is what a halogen lamp does).

ViReN,

Just wanted to clarify/add to mattheww50's excellent (as usual) post:

Xenon and Krypton are both Halogen's: so when you say "halogen" you mean either one or the other. Halogen is a general term indicating elements in a column of the periodic table, IIRC.

Xenon lamps are, from what I've seen, better than Krypton lamps.

Normal lamps are always worse than halogens, from what I've seen, but I think they run cooler.

And who's to say what new technologies may or may not come along. Everyone assumes that incans will go the way of the dinosaur, and they probably will, but it's not a done deal. It's not certain. Perhaps there will be another break through like the advent of the halogen lamp, and incans will get a new lease on life. We shall see.

Oh, and matthew, I checked the melting temp of Tungsten and it's 6000+ degrees F! Holy Cow! Perhaps the CCT is the filament temp after all. I don't know. I would think that that kind of temp at the filament, would mean heat conduction down to the normal metal lamp leads and would melt them. Plus the CCT means "correlated color temperature". Wouldn't they just call it filament temperature if the FT=CCT? Eh. Not sure. But I find it hard to believe that the filament really is 3400 F in a "hot" xenon lamp. I'll look into it some more, unless you have a definitive answer.

hang on a tic - both xenon and krypton are halogens ?
so what is in a globe that is marketed as a halogen ?
like the headlight globes

and what about the quartz iodine/iodide globes (like car headlights)

The gas fill of a lamp marketed as "halogen" can be either xenon or krypton.

Not sure about the iodine globes. Wild guess: probably iodine at a lower than 1 atmosphere pressure. Iodine is a liquid at standard temperature and pressure. Lower the pressure or raise the temperature and it turns into a gas.

The halogens are in the VIIIA column of the periodic table of the elements and include, in acsending order of atomic weight: Helium, Neon, Argon, Krypton, Xenon, and Radon.

Echo, none of the bulbs, including the car bulbs, so far as I know actually have only ONE gas in them. The proprietary mix is what distinguishes the bulbs from each other and from manufacturer to manufacturer.

Some have more Xenon, some more Krypton, some more Iodine, some more bromine, etc.

Bill

Does anyone know how long to keep a flashlight on to insure that a complete halogen cycle will take place? Does the glass globe, itself, need to reach a high enough temperature or just the filament and gas?

Great Responses... THanks Dudes /ubbthreads/images/graemlins/smile.gif

I was really unclear about the things....

In early days... there were just 2 types of bulbs (that i know) ... the normal bulbs (the dull ones) & the Halogen's ... the brighter ones... mostly used for lighting special applications like spot lights & Vehicle Head Lamps...

Off late.... Krypton & Xenon were in the market....

Xenon (Headlamps.. for car)... i think is wrongly being marketed... they use a Blue Glass filter to product whiter light....where as normal halogen's dont use any kind of filters ... some of the fog lights are coated with a very thin layer of gold to produce a yellow light i guess...

-ViReN

I am positive that Halogens are in Group 7 of the periodic
table and are Fluorine, Chlorine, Bromine, Iodine etc.

Xenon and Krypton are DEFINITELY not halogens, but
inert gases as mattheww50 said.

My understanding is that a Halogen filled lamp allows the "Halogen Cycle" to prolong the lifespan of the Tungsten filament. Xenon is a gas used at high pressure to make it more difficult for the Tungsten to evaporate from the filament in the first place. Therefore a high pressure Xenon/Halogen bulb can be driven harder - for brighter, whiter light.

Al

Right,
Group 8 are the noble elements. Group 7 are halogens.
Wilkey

I believe that the halogen lamps contain halide salts while xenon and krypton are the nobel gases that are added to the Xe and Kr bulbs to allow higher internal pressures than argon type would allow.

[ QUOTE ]
js said:
And who's to say what new technologies may or may not come along. Everyone assumes that incans will go the way of the dinosaur, and they probably will, but it's not a done deal. It's not certain. Perhaps there will be another break through like the advent of the halogen lamp, and incans will get a new lease on life. We shall see.


[/ QUOTE ]
About the only thing I see giving incandescents a new lease on life is a new filament material that can be run at maybe 5000K to 6000K. Combine that with coatings to reflect the IR and UV from the filament back into the bulb so as to lower heating requirements, and you may very well see an incandescent with well over 100 lm/W efficiency that also gives a nice white light instead of the "off-white" typical of incandescents. Short of that, however, I see the incandescent light dying out eventually as LEDs with much higher efficiency, longer life, better color temp, and CRIs approaching 100 are made.

[ QUOTE ]

I checked the melting temp of Tungsten and it's 6000+ degrees F! Holy Cow! Perhaps the CCT is the filament temp after all. I don't know. I would think that that kind of temp at the filament, would mean heat conduction down to the normal metal lamp leads and would melt them. Plus the CCT means "correlated color temperature". Wouldn't they just call it filament temperature if the FT=CCT? Eh. Not sure. But I find it hard to believe that the filament really is 3400 F in a "hot" xenon lamp.

[/ QUOTE ]
Actually, the filament does run at the CCT, and I think with most incandescents they just call it color temp rather than CCT. CCT is only necessary when the emitted radiation falls off the Planckian locus. Since a filament is for all intents and purposes a blackbody this isn't necessary. CCT only comes into play for incandescents when you use filters to get higher color temps. Solux has a line of MR-16 halogen lamps in color temps of 3500K, 4100K, and 4700K. Obviously the filament doesn't operate anywhere near those temperatures. CRI is said to be 99+.

BTW, I think you meant 3400K, not 3400°F, as the temperature of a hot xenon lamp (3400K = 5660°F). This isn't far from the melting point of tungsten, and represents the limit that an incandescent light can operate at (maybe you can go to 3500K, but the filament will die within seconds or minutes at most).

[ QUOTE ]
cannon50 said:
I believe that the halogen lamps contain halide salts while xenon and krypton are the nobel gases that are added to the Xe and Kr bulbs to allow higher internal pressures than argon type would allow.

[/ QUOTE ]

I thought I had this all figured out but now I'm confused again. My understanding is:

-Halogen is not an element but a class of elements
-Xenon and krypton are the two most popular inert gses that fill high intensity bulbs,(either individually or in combination)?
-Some members of the halogen family (iodine, bromine etc?)are added to "sweeten" the xenon/krypton performance
-The "halogen cycle" is the redepositing of burned-off tungsten back to the filiment, made possible by the high internal pressure and the nature of the inert gases. This occurs only when filiment temperature is high enough which is why keeping voltage up is so important.

Will someone please correct this and state the facts in clear, complete and concise terms so I can finally understand this?

Brightnorm

they already have HIR (Halogen Infra Red), bulb is spherical over the filament section, coated in IR reflecting materials, allowing better output; take the example of 9006 headlamps; nominally 1000 lumens, HIR outputs 1900 lumens.

[ QUOTE ]
easilyled said:
I am positive that Halogens are in Group 7 of the periodic
table and are Fluorine, Chlorine, Bromine, Iodine etc.

Xenon and Krypton are DEFINITELY not halogens, but
inert gases as mattheww50 said.

[/ QUOTE ]

Oops. Yes. That column is NOT the halides. Sorry.

As Bill said, the fill of a halogen lamp contains a mix of gases, including one or more of the non-reactive noble gases.

[ QUOTE ]
jtr1962 said:
[ QUOTE ]
js said:
And who's to say what new technologies may or may not come along. Everyone assumes that incans will go the way of the dinosaur, and they probably will, but it's not a done deal. It's not certain. Perhaps there will be another break through like the advent of the halogen lamp, and incans will get a new lease on life. We shall see.


[/ QUOTE ]
About the only thing I see giving incandescents a new lease on life is a new filament material that can be run at maybe 5000K to 6000K. Combine that with coatings to reflect the IR and UV from the filament back into the bulb so as to lower heating requirements, and you may very well see an incandescent with well over 100 lm/W efficiency that also gives a nice white light instead of the "off-white" typical of incandescents. Short of that, however, I see the incandescent light dying out eventually as LEDs with much higher efficiency, longer life, better color temp, and CRIs approaching 100 are made.

[ QUOTE ]

I checked the melting temp of Tungsten and it's 6000+ degrees F! Holy Cow! Perhaps the CCT is the filament temp after all. I don't know. I would think that that kind of temp at the filament, would mean heat conduction down to the normal metal lamp leads and would melt them. Plus the CCT means "correlated color temperature". Wouldn't they just call it filament temperature if the FT=CCT? Eh. Not sure. But I find it hard to believe that the filament really is 3400 F in a "hot" xenon lamp.

[/ QUOTE ]
Actually, the filament does run at the CCT, and I think with most incandescents they just call it color temp rather than CCT. CCT is only necessary when the emitted radiation falls off the Planckian locus. Since a filament is for all intents and purposes a blackbody this isn't necessary. CCT only comes into play for incandescents when you use filters to get higher color temps. Solux has a line of MR-16 halogen lamps in color temps of 3500K, 4100K, and 4700K. Obviously the filament doesn't operate anywhere near those temperatures. CRI is said to be 99+.

BTW, I think you meant 3400K, not 3400°F, as the temperature of a hot xenon lamp (3400K = 5660°F). This isn't far from the melting point of tungsten, and represents the limit that an incandescent light can operate at (maybe you can go to 3500K, but the filament will die within seconds or minutes at most).

[/ QUOTE ]

AH! Thanks for this! That makes sense.

jr1962,

So if the filament is running that hot, why doesn't it melt the electrical/mechanical wires which hold it in position?

[ QUOTE ]
js said:

And who's to say what new technologies may or may not come along. Everyone assumes that incans will go the way of the dinosaur, and they probably will, but it's not a done deal. It's not certain. Perhaps there will be another break through like the advent of the halogen lamp, and incans will get a new lease on life. We shall see.


[/ QUOTE ]

I guess you haven't seen photonic lattices yet?

http://www.sandia.gov/media/NewsRel/NR2002/tungsten.htm

"This could raise the efficiency of an incandescent electric bulb from 5 percent to greater than 60 percent."

This would raise the efficiency by 1,200%

NewBie, I'll check that out.

I have a bad tendency to think I know what I'm talking about when I really don't know what the (*&T^! I'm talking about.

In an attempt to remedy this I have started researching tungsten halogen lamps. I thought this link would be worth while to post for the benefit of our discussion and to help answer some of the questions that were originally asked. I'll be back later when I have a clue or maybe more than just one clue. Sorry everyone.