Thanks Jorge...I have read Dick Arentz's book, but it seems I need a refresher. The facts about Kelvin Temp as related to the electromagnetic spetrum is as follows:

"UV radiation is light created by processes more energetic than those
that produce visible light. For example, the light one sees from the
Sun is produced at the solar surface, at a temperature of about
10~340 degrees Fahrenheit (6000 degrees Kelvin). The Sun also
produces ultraviolet light, from the much hotter gases that lie above
the surface, at temperatures of 17~540 to 179,540 degrees
Fahrenheit (10,000 to 100,000 degrees Kelvin)."

Now I know I'm not going to find a lamp at 10kKelvin, so I'm shooting for the next best thing, which is the higher end of sunlight. I want to filter out the lower end of the spectrum, which will have a higher percent of the "unwanted" red energy, and get a higher percent of the "blue" light energy, which is where ultraviolet starts to live. I'm just wondering if I can filter out (most) everything lower than blue light (so repeated exposures will be nearly identical no matter what the intensity of the sun is). Will a neutral density filter do that? I want to raise the capture of sunlight intensity, not lower it.

Anyhow, I know that some of the lamps used in the NuArcs are strictly for UV exposure, and they have their own light integrator (can't remember what it is called or how much it costs). I don't think this is the case for the Metrolux. I suspect the Metrolux bandwidth is much wider than the NuArc light integrator bandwith. My question is whether the Metrolux is worth working with, for the price, to adapt to a strictly UV situation...

I'm going to have to reread that Arentz book...don't remember this being discussed?? Thanks again for the push in the right direction...
Cathy