At 09:11 AM 12/17/98 -0800, you wrote:
>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.

The wavelength of radiation is measured in nanometers (or angstroms: an
angstrom is a tenth of a nm), which are a unit of length. Depending only on
the wavelength, electromagnetic radiation can be top-40 radio, TV, X-rays,
infrared, ultraviolet, and a bunch of other things. Between 400 and 700
nanometers  we can see EM radiation and call it light.  Shorter waves than
about 300 (but longer than, say, Xrays) are invisible to us, give you
sunburn and damage your art, and are called ultraviolet (bees can see it,
though).  Wavelength tells you nothing about how much radiation is being
emitted, just what kind.  Also,  radiation between 400 and 700 isn't
ultraviolet, so Philips' response is not only useless but meaningless; you
asked how many apples they have and they say "our apples are all Valencia,
which are actually oranges".  i'm sure they aren't claiming no uv from
these lamps.

mW/l describes the amount of ultraviolet energy emitted with a unit of
visible light energy,  which is what you want to know, your standards give
you maximal values for this so you can see the objects without ruining
them.  Philips should be able to tell you this.  You need to ask the rep to
connect you to someone who knows what light is and can give you a coherent
technical answer.