At 21:25 15/07/97 +0100, you wrote:
>Halogen lights give off a load of uv - thats why they need a glass plate
>over the bulb and you should be further than a metre away at all times.  It
>could be erasing the chip.
>
>Tim
>

Hmm, not all that much u.v. They have a colour temperature around 3200K
(sorry photograpy creeping in) which is similar to a domestic light bulb.
They emit a little more uv because the tube is silica rather than glass.

AFAIK the reason most of them have a glass plate in front is because they
frequently fail with a bang. Being sprayed with lots of red hot quartz
fragments is no fun (been there, done that).

Keith.
==========================================================
Keith Dowsett         "Variables won't; constants aren't."

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