Ultraviolet output from common 35 Watts automotive metal halide HID bulb(s)

Dr. Mario

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Mar 4, 2010
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:thinking: Sometimes I really can't help it but wondering... I am more of a "Question" guy.

However, after getting a new slim ballast installed in my modded Cyclop Thor Colossus (previous ballast misbehaved resulting in Xenon Metal Halide bulb flickering (and sputtering all over the hot Quartz glass) so I ended up getting free replacement, I will repair this one eventually), I decided to whip out my old prescription eyeglass which has Transition coating (which darkens down in presence of ultraviolet light) just for sh*t and giggle, however.... :green: Much to my surprise, my modded spotlight darkened the glass within a minute...

(In comparison, my NVSU233A blacklight flashlight darkens the coated glass in a second. It's that powerful. :aaa:)

Apparently, the Cerium doping isn't really doing very much to block the UV light (although the doping is evident when shining the blacklight onto the HID bulb; it glows sky blue under 365nm UV lamp), nor do the tempered glass. (And yes, the outer envelope is still intact.) Guess I am getting a lot of Vitamin D. :crazy:

That notion really tempted me... What if I buy 30,000 Kelvins purple 35 Watts metal halide HID (popular with ricers :sick2: and it tend to emit a lot of ultraviolet due to blackbody temperature of the metal salts used therein, would be interesting to see the ricers complaining that their headlights are UV damaged when in fact they put in the UV metal halide bulbs) and put it in a lantern with a surplus large Wood's Glass in the front of the reflector...? It would possibly make for a powerful blacklight lantern. :devil:
 
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FRITZHID

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I've used a UV pass filter on my Stanley and my maxabeam... The Stanley is 35w with standard bulb and does a fine job florescing objects for quite some ways, however, when I removed the outer tube from the bulb and removed the stock lens, this improved greatly. The maxabeam is powerful right out the gate but having 1/3 the lumens, was only useful in spot mode. I know if you fire up a maxabeam without the lens, you can smell o3 very strongly, leading me to believe there's a far higher amount of UV coming from the xenon SA vs. standard MH type bulbs.
Just my 2¢.
 

Dr. Mario

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Mar 4, 2010
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That's kind of what I thought; if I removed the outer glass shroud, it would have produced interesting results. On a note, I know metal halide bulb itself don't generate that much UV in the germicidal wavelength (responsible for ozone generation), while Xenon gas itself has several UV-C spectral lines.

Metal halides themselves may probably emit some UV-B (usually a lot of UV-A as the electrons are hitting them hard, a bit like Bremsstrahlung process, only mainly in the UV-A and occasionally B bands), but rarely in the UV-C unless metal salts with wide electron bandgaps are used like Mercurial iodide or Mercurial Chloride. Also, the HID lamps that dump a lot of UV-C would warranty UV stop glass to kill the UV-C lights off (while resisting heat generated by absorption of several watts of UV-C light), and special glass molded reflector as cheap reflectors' coatings would flake under presence of either nastier UV and / or Ozone.

On a side note, I wonder about the 75 Watts Mercury vapor XBO short-arc tube lamp - it can be run off battery via special switchmode ballast (I would be able to assemble one from scratch, however, I would have to find a datasheet on current waveform requirement and several other important electrical parameter). Due to its Mercury amalgam (or salt) filling, it may be able to emit a lot of UV light, while with UV-A bandpass filter removed, useful for searchlight usage. I'd need 20 Amps hour Lithium-ion battery pack to be able to run that lamp for up to two hours maximum.
 
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Dr. Mario

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And plentiful of multi-clusters of UV-A lines too, ranging from 393.7 nanometers, down to 321.3 nm for Xenon-Mercury ionic mixture (such as the environment in the XBO bulb).
 
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