Firstly, my understanding is that
ultraviolet light ranges in wavelength
from 400nm down to smaller values.
That is, the statement "The UV
wavelength is 400-700nm which is
visible light" doesn't make sense. The
implication of the statement is that
the tubes emit no UV, but I would
want to see a graph of that as there
may not be a sharp cut off at 400.

Secondly nanometres are a measure
of wavelength. MicroWatts per lumen
are a measure of energy. They cannot
be converted. What you want is how
many MW/lumen are being produced
at a certain range of of frequencies -
i.e. how many of UV.

Philips do have charts and such on
their tubes. Extracting the information
from a supplier is not necessarily
easy though.

Someone else on the list may already
have info on this particular tube. Hope
this is of some use. I am NOT an
expert but am fairly sure of the above.

> We recently purchased TL 70 series fluorescent lamps (bulbs and tubes) for
> our museums and will be used in all of our exhibit spaces. I asked the
> manufacturer, Philips Lighting, what the UV output of these bulbs are and
> they answered "The UV wavelength is 400-700 nanometers which is visible
> light." The problem is that the museum literature I have on lighting
> refers to "microWatts per lumen" or mW/l.  Does anyone know how to
> calcuate the nanometers into mW/l so I can really understand how much UV
> is being emitted by these new bulbs? I assume that I need to put a UV
> filter over each bulb. Thanks for any help!
>
> Mary Ames Sheret
> Curator of Collections/Exhibits
> Southern Oregon Historical Society




______________________________________

Athol McCredie
Curator
MANAWATU ART GALLERY
398 Main St, Private Bag 11-055,
Palmerston North, New Zealand
Ph 06 358-8188; Fax 06 358-8849
_______________________________________