8mm Forum: Radiation from Arc Lighting

This is topic Radiation from Arc Lighting in forum 16mm Forum at 8mm Forum.

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Posted by Simon McConway (Member # 219) on May 21, 2005, 06:04 PM:

I use a projector which has a G E MARC 300 high-intensity arc lamp. This lamp is NOT a xenon. I have heard people suggesting that radiation is a risk associated with arc lighting. Can anyone confirm this?

Posted by Alan Gouger (Member # 31) on May 23, 2005, 12:30 PM:

I have been using Arc lamps for years and have noticed no side effects.

Posted by David Pannell (Member # 300) on May 23, 2005, 01:09 PM:

The most serious effect is of course arc-eye, which literally burns the retina of the eye. You should only look at an electric arc through a welders mask.

With regard to radiation, the electric arc emits EVERY wavelength in the ultra violet spectrum and is, of itself, extremely hazardous, causing cancer and all the other related nasties. It is more intense than being exposed to the sun and can do far greater damage.

HOWEVER - HEAR THIS!! The glass or quartz envelope in which the arc is contained, filters out pretty much all of this UV radiation!

So, you're OK with your arc projector lamp. Nevertheless, if the glass bulb is damaged in any way, ie. scratched or grazed, throw it away, because the harmful radiation will get through. Even if the interior of the bulb is still smooth, the radiation is only properly filtered by the total internal reflection of both the inner and outer surfaces of the glass.

Here endeth the lesson. [Eek!]

Dave.

Posted by Michael De Angelis (Member # 91) on May 30, 2005, 09:39 PM:

David & Alan,

David, this was very informative.
Yikes Alan, I like the formal wear and Bow tie, but it is
a informal forum!

But thanks for the special effects. Nice trick, it's great. [Big Grin]

Michael

Posted by John A. Pommon (Member # 292) on June 04, 2005, 01:36 AM:

Be sure the welding filter shade is correct for your application. I use an Omni-View #10 shade for observing 550 w arc lamp. (O.V. meets/exceeds ansi Z87.1 standards)

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