Hello all:

I am writing to clear up some confusion about the UV output of
halogen light bulbs.

I had an inquiry from a friend who runs a small, but  respectable,
private quilt museum behind her antique shop in a small town near
here.  She really does a good job at maintaining high standards and
is conserned about conservation, etc.  She called to tell me that a
visitor this morning told her she needs filters on her halogen flood
lights in the museum and that she was ruining her quilts.   She
wanted to know what I knew about halogen.

My initial response to her need for filters was "nonsense." Her flood
lights are about 20 ft. from the textiles on exhibit (so heat is not
an issue), and I'd say the light level is about 10 footcandles.  The
lights are only on when there is a visitor to her museum room, and
she rotates her exhibits every few months.  But then I thought about
it and curiosity made me look it up in some reference materials and I
discovered from a chart that tungsten halogen bulbs produce as much UV
as fluorescent bulbs.  I also checked the Consdist List archives
(CoOL) and could find scant information there, but what I did see
hinted that halogen bulbs might actually be better than fluorescent
for UV output.  The Museum-L archives had nil (that I could find) on
this topic.

So....
1.  Do tungsten halogen bulbs put out more UV than regular
incandescent bulbs?  As much as UV as fluorescent?
2.  Are all halogen bulbs tungsten bulbs?  If there is such as thing
as non-tungsten, are they better or worse?
3.  Can anyone recommend a cheap source for UV filters?

If she does need filters, perhaps it would be better and cheaper to
just replace the halogen flood bulbs with regular incandescent flood
bulbs.

Can anyone help?  Thanks!

Christine Mouw
Assistant Curator
Herbert Hoover Presidential Library-Museum
West Branch,  IA  52358
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