How much better is xenon over krypton?
- Thread starter Genxsis
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It all depends.
In general, a xenon filled bulb is brighter and whiter than a similiar krypton bulb. Except that in general krypton filled bulbs can stand more 'overdrive' before instaflashing than a similiar xenon filled bulb. The overdriven krypton bulb may be whiter and brighter than the spec-driven xenon filled bulb. But that's due more to that fact that it is overdriven.
So, it all depends.
In general, a xenon filled bulb is brighter and whiter than a similiar krypton bulb. Except that in general krypton filled bulbs can stand more 'overdrive' before instaflashing than a similiar xenon filled bulb. The overdriven krypton bulb may be whiter and brighter than the spec-driven xenon filled bulb. But that's due more to that fact that it is overdriven.
So, it all depends.
Nubo
Enlightened
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- Dec 23, 2004
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- 461
The way I understand it is, the purpose of the fill gas is to decrease the tendency of Tungsten atoms to leave the filament. A particular atom of Tungsten reaches enough energy to launch it from the filament, but bumps into a gas molecule, preventing it from leaving.
To improve the benefits of the fill gas you can do a couple of things
- you can increase the density of the gas molecules. The more gas molecules, the more likely that "overheated" tungsten atoms will bounce into one of them instead of slipping away from the filament. To increase the density means using more gas. Once you reach atmospheric pressure, to increase the gas density means pressurizing the bulb. Extreme high-performance bulbs can have pressures of 5, 10, 20 or more times atmospheric pressure. That's why high performance bulbs should always be enclosed (i.e. behind a lens) before being turned on.
-the second way to improve the fill gas is to use heavier molecules. The quintessential "house bulb" uses an Argon fill gas. Argon has atomic number of 18. The next "inert" gas on the periodic table is Krypton, at atomic number 36. Much larger and heavier atoms. Xenon, at atomic number 54 is heavier still. I suppose one could consider Radon, at atomic number 86 (higher than Tungsten itself), but that could be dangerous
In the real world, other factors come into play. It's all about the balance that the manufacturer tries to achieve. Xenon is theoretically a better fill gas, all other things being equal. But, a particular Xenon bulb may already be pushing the edge, trying to take maximum advantage of the Xenon fill and running the filament very close to the melting point. If a manufacturer goes to the trouble of using Xenon they probably want the customer to "see" the difference, to justify the more expensive material. While a Krypton bulb of similar volts rating may be compensating for the less efficient gas by incorporating a thicker filament -- thus being more amenable to overdriving.
So, in the real world, if you are using the "recommended" bulb for a mass-produced light, the Xenon will probably outperform. If you're outside of those parameters then you will be juggling output vs. bulb life at voltages they were not designed for. For this you need to know the specs at "nominal voltage" and extrapolate either using mathematical rules-of-thumb...
https://www.candlepowerforums.com/threads/111203
Or by experience from others, or by direct experimentation.
To improve the benefits of the fill gas you can do a couple of things
- you can increase the density of the gas molecules. The more gas molecules, the more likely that "overheated" tungsten atoms will bounce into one of them instead of slipping away from the filament. To increase the density means using more gas. Once you reach atmospheric pressure, to increase the gas density means pressurizing the bulb. Extreme high-performance bulbs can have pressures of 5, 10, 20 or more times atmospheric pressure. That's why high performance bulbs should always be enclosed (i.e. behind a lens) before being turned on.
-the second way to improve the fill gas is to use heavier molecules. The quintessential "house bulb" uses an Argon fill gas. Argon has atomic number of 18. The next "inert" gas on the periodic table is Krypton, at atomic number 36. Much larger and heavier atoms. Xenon, at atomic number 54 is heavier still. I suppose one could consider Radon, at atomic number 86 (higher than Tungsten itself), but that could be dangerous
In the real world, other factors come into play. It's all about the balance that the manufacturer tries to achieve. Xenon is theoretically a better fill gas, all other things being equal. But, a particular Xenon bulb may already be pushing the edge, trying to take maximum advantage of the Xenon fill and running the filament very close to the melting point. If a manufacturer goes to the trouble of using Xenon they probably want the customer to "see" the difference, to justify the more expensive material. While a Krypton bulb of similar volts rating may be compensating for the less efficient gas by incorporating a thicker filament -- thus being more amenable to overdriving.
So, in the real world, if you are using the "recommended" bulb for a mass-produced light, the Xenon will probably outperform. If you're outside of those parameters then you will be juggling output vs. bulb life at voltages they were not designed for. For this you need to know the specs at "nominal voltage" and extrapolate either using mathematical rules-of-thumb...
https://www.candlepowerforums.com/threads/111203
Or by experience from others, or by direct experimentation.
Navck
Enlightened
Nubo said:The way I understand it is, the purpose of the fill gas is to decrease the tendency of Tungsten atoms to leave the filament. A particular atom of Tungsten reaches enough energy to launch it from the filament, but bumps into a gas molecule, preventing it from leaving.
To improve the benefits of the fill gas you can do a couple of things
- you can increase the density of the gas molecules. The more gas molecules, the more likely that "overheated" tungsten atoms will bounce into one of them instead of slipping away from the filament. To increase the density means using more gas. Once you reach atmospheric pressure, to increase the gas density means pressurizing the bulb. Extreme high-performance bulbs can have pressures of 5, 10, 20 or more times atmospheric pressure. That's why high performance bulbs should always be enclosed (i.e. behind a lens) before being turned on.
-the second way to improve the fill gas is to use heavier molecules. The quintessential "house bulb" uses an Argon fill gas. Argon has atomic number of 18. The next "inert" gas on the periodic table is Krypton, at atomic number 36. Much larger and heavier atoms. Xenon, at atomic number 54 is heavier still. I suppose one could consider Radon, at atomic number 86 (higher than Tungsten itself), but that could be dangerous
In the real world, other factors come into play. It's all about the balance that the manufacturer tries to achieve. Xenon is theoretically a better fill gas, all other things being equal. But, a particular Xenon bulb may already be pushing the edge, trying to take maximum advantage of the Xenon fill and running the filament very close to the melting point. If a manufacturer goes to the trouble of using Xenon they probably want the customer to "see" the difference, to justify the more expensive material. While a Krypton bulb of similar volts rating may be compensating for the less efficient gas by incorporating a thicker filament -- thus being more amenable to overdriving.
So, in the real world, if you are using the "recommended" bulb for a mass-produced light, the Xenon will probably outperform. If you're outside of those parameters then you will be juggling output vs. bulb life at voltages they were not designed for. For this you need to know the specs at "nominal voltage" and extrapolate either using mathematical rules-of-thumb...
https://www.candlepowerforums.com/threads/111203
Or by experience from others, or by direct experimentation.
Well, if you filled the bulb with Radon, I don't think having batterys will be a problem. However, blown bulbs WILL be a big one here. It'll be like tritium vials, but on the NEXT level. :laughing:
FirstDsent
Enlightened
I say try Radon:
1. Even at 20 Bar that's not much gas
2. Its not very radioactive/toxic
3. If I break a fluorescent tube I already know I shouldn't breathe the vapor. Why should a HP Radon bulb be any different.
4. Huffing a broken Radon bulb is probably more benign than smoking a cigarette.
I'll be happy to beta test a Radon hotwire!
Bernie
1. Even at 20 Bar that's not much gas
2. Its not very radioactive/toxic
3. If I break a fluorescent tube I already know I shouldn't breathe the vapor. Why should a HP Radon bulb be any different.
4. Huffing a broken Radon bulb is probably more benign than smoking a cigarette.
I'll be happy to beta test a Radon hotwire!
Bernie
Nubo
Enlightened
- Joined
- Dec 23, 2004
- Messages
- 461
Genxsis said:
That just means I did a poor job of explaining.
If your interested, here is a wonderful site about all of the elements. Argon, Krypton, Xenon and the other "noble gasses" are on the far right column of the table. There's also plenty of interesting information on most other elements, including the ones that have been used for incandescent lightbulb filaments -- Tungsten (of course), Carbon, Tantalum, Osmium and Platinum
. The gentleman has a great way of presenting info and you don't have to be super-technical to enjoy it.http://www.theodoregray.com/PeriodicTable/
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