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Twospoons
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Near as I can work out halogens go down to 250nm, but the output is quite low.
The vast bulk of the radiation is in the IR. Only 1% of the output is in the UV range under 400nm.
Helicopter: "helico" -> spiral, "pter" -> with wings
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Mr. Wizard
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Even 1% of a 100 watt bulb is a terrific source of UV. The bulbs are dirt cheap and can be run with only convection cooling. If electricity is that
expensive where you live, maybe the UV LEDs would make sense. Sunlight is even cheaper, but not as convenient, as many have mentioned.
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IrC
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I figured all along that Bromic just had these LEDS and wanted to find a cool use to play with them. If I were actually going to build the reaction
setup mentioned I would use one of those 18 inch 20 watt fluorescent germicidal lights. Much more UV in the short end of the range, little heat and
little electricity used, plus it can be on 24 hours a day if needed without worry of any failures or other problems.
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Organikum
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vulture, I don´t know the wavelengths emitted by the halogen lamps, but I know from experience that a 150W halogen without the shielding glass works
the same or even better than a dedicated 60W UV lamp.
Don´t forget that shorter wavelengths are filtered out by the glass anyways.
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Eclectic
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Quartz Mercury Arc
http://www.aceglass.com/html/products/support_info/photochem...
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Mr. Wizard
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I have a few of these mercury vapor quartz lamps with fused quartz or silica protective tubes. GPH287T5L rated at 14 watts. They are called non ozone
generating germicidal lamps. They have a big test tube surrounding them. Does anyone know how to tell if the big tube surrounding the discharge tube
is quartz or just glass? I don't know what the spectrum is either, just that it's for 'germicidal use" and "non
ozonating."
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Mr. Wizard
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Picture of lamps in previous post.
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neutrino
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Try heating the tubes with a blowtorch. If the glass gets red hot without softening or having any orange sodium vapor come off it, it's quartz.
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vulture
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If it's none ozone generating, it's a safe bet the wavelengths emitted won't drop below 280nm.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Mr. Wizard
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I think the majority (95%) will be around 254 nm according to this site.
http://www.ultraviolet.com/whatis.htm
The ozone producing band is produced by the Hg vapor at 185 nm and is only a small percentage of the output. What wavelength forms the O3?
I'll test the sleeves I have to see if they are quartz. I'll clean them first to remove any surface contamination then get them red hot and
see what happens.
[Edited on 3-8-2005 by Mr. Wizard]
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Mr. Wizard
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It looks like quartz. I cleaned it with tap water, wiped it dry.
1 warm up
2 full heat with propane weed burner
3 red glow, doesn't seem to glow much compared to other things.
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Mr. Wizard
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I haven't figured out how to attach two jpeg files yet. Here is the tube while under high heat. Notice there is no sodium glow.
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12AX7
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Sounds good, anything else would've melted by then. 8)
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Twospoons
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My workmate and I are looking at buying a wafer of 400nm UV LED die from Cree (about 6000 die) and getting them bonded into TO3 size multi-cavity
packages. This would put 300 die into a space of 1 square inch, with a UV flux of around 3W. I'm just curious if anyone here would be
interested in such a device (we want them for UV glue curing), as we'll probably offer them for sale (couldn't guess a price though!).
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12AX7
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Wow, hooking up a whole LED slice? That would be AWESOME, UV or otherwise! 
d00d...can you imagine a full sheet of Luxeon Stars? 
Tim
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Twospoons
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Our first cure lamp consisted of 3, just 3, of the 5W royal blue Luxeons (700mW output each). The result was scary. Those Luxeons are just
incredible. Shame they don't do UV.
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Lambda
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LED related schematics
LED related schematics:
http://www.commlinx.com.au/LED.htm
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SAM4CH
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UV Lamp
I have UV lamp (TLD15W/05 PHILIPS 15W T8), and I like to make photochlorination reaction So how can I operate my lamp safty and what about its
connections?
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neutrino
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Consult the product manual and / or manufacturer if you want to know how to run the lamp. I'm assuming that's what you mean by 'connections'.
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Twospoons
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On the subject of LEDs as UV sources, we've just acquired some excellent ones from Cree. In their Xlamp package, they put out 200mW @ 400nm , with a
supply of 350mA @3.5V. With a solid heatsink I've pushed them to 800mA ( ),
almost doubling the light output. They cost US$9 each.
I'm also trying to get some 380nm, 150mW ones from Hanse.
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vulture
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| Quote: |
On the subject of LEDs as UV sources, we've just acquired some excellent ones from Cree. In their Xlamp package, they put out 200mW @ 400nm
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I see alot of this...but 400nm isn't UV! A quick test in the analytics lab with a difraction grating showed that most people can still see light up to
350nm.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Twospoons
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400nm is short enough to appear quite dim. And 200mw is uncomfortable to look at. I had 3 running yesterday, giving me 1 watt of 400nm. I have
455nm Leds that put out 700mW, and I can't look at them.
I think the definition of what contstiutes UV is somewhat arbitrary. At the IR end, 850nm is consider well into the IR, yet it is faintly visible in
the dark.
Helicopter: "helico" -> spiral, "pter" -> with wings
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Texium
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Thread Moved
19-11-2023 at 11:21 |
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