[Alt-photo] experience with UV light meters

John Isner john.isner at gmail.com
Sat Nov 10 22:35:54 UTC 2018


Has anyone tried the Light Controller LC2 System from Ian Leake Studio
<https://ianleake.com/light-controller-lc2-system/>?  If so, how do you
like it compared with the PPM-2 meter, which seems to be somewhat popular
on this listserv?  A big advantage of the LC2:  it has an optional power
controller that can turn off the exposure unit when it reaches a specified
dose, while the PPM-2 must be watched.  Of course you pay a lot extra for
that power controller!  I assume both meters do an equally good job of
measuring dose.

The PPM-2 displays instantaneous intensity as well as total dose.  For the
last two days, I have been testing my UV exposure unit with a borrowed
PPM-2.  I initially thought a plot of Intensity vs. time would tell me
something about my bulbs.  But I find the intensity display to be less
useful than I had hoped.  The numbers move so erratically that it is hard
to spot a trend.  If the PPM-2 displayed a 5-second moving average, it
would be more useful.

One conclusion I have reached, after running many tests with the PPM-2, is
that my UV unit (fifteen  actinic fluorescent tubes, five electronic
ballasts, all less than six months old) is behaving very erratically.  For
ten minute exposures, even with a long preliminary warm-up, the dose can
vary as much as 2/3 of a stop.  This tells me I MUST switch from time-based
exposure to dose-based exposure.  The question is whether I should I go
with the PPM-2 or the LC2 system.


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