Re: case plastic yellowing question

[russotto@grace.speakeasy.net (Matthew Russotto)]

In article <WHozc.18807$H65.6703@nwrddc02.gnilink.net>,
Sam Gillett <samgillettnospam@diespammermsn.com> wrote:
>
>"Blake Patterson" <blake@blakespot.com> wrote ...
>
>> Hmmm - wonder if I should just dump that light.  Halogen any worse
>> than other type of lite?  (So sunlight ever hits these (dark basement)
>> and other light is mainly soft white low-wattage bulbs behind.)
>
>Haven't seen any definitive proof one way or the other.  But have been told
>that halogen lights produce more UV than conventional lighting.  And that
>does seem to be logical.  Why else would so many halogen lights be equipped
>with UV filters?

Tungsten-halogen bulbs have a quartz envelope, rather than a glass
one.  Quartz passes UV a lot better than ordinary glass.  They also
probably produce slightly more UV because they're hotter than ordinary
tungsten bulbs, but the lack of natural filtering in the bulb glass is
the major effect.