Re: UV light output over life of source
William Laven (William_Laven@designlink.com)
17 Jul 1995 07:21:41 GMT
The Metrolux II measures light output over a fairly broad spectrum. (For those
unfamiliar with this wondeful timer, it uses a closed loop feddback system,
like a plate burner light integrator, and measures by light output, not time,
thereby offering perfect exposure consistency.) If you wanted to measure just
UV light with the Metrolux, you could replace the light sensor they supply
with one made by NuArc; they cost around $85 I think. However, it might be
unnecessary. My Metrolux, fitted with the cell they supplied, has given me
consistent exposures over the six years I've had it attached to my UV
printer. UV bulbs are actually pretty consistent; they burn for awhile at one
output, then drop about 15% (which the Metrolux, of course, sees) but over
the course of an exposure or over years of use, they are relatively stable.
The Metrolux guarantees your exposures will be consistent, though, even with
the teeniest variations in light output. I doubt you'll need to replace the
bulbs.
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