You said:
> A question for clarification. When you say high pressure mercury bulbs,
>do you mean a special bulb that is used in a device similar to what we
>call a "plate burner?" If so, the cost of these devices put them out of
>reach of many list members and hence the interest in Fl tubes.
When I was still a ' suit ', but obsessive about gum printing, I checked to see
what lamps people were using when they exposed for images using dichromated
colloids.
Pulsed xenon cost more than its colour temperature in pounds sterling and black
light tubes tubes were inflexible and expensive for twenty sixteens.
The local art college, and nearly every other one I have been in since, used a
Philips HPR 125 High Pressure Mercury Vapour Ultra Violet bulb. They are used
in fashion, ceramics, printing, art and other departments. And, of course
commercially.
The lamps give an even spread of light of four feet diameter at four feet from
the bulb.
Twenty years ago they cost forty pounds together with the ballast and capacitor
which was the same as the cost of four tubes with two starters and ballasts. The
bulb fits a standard ES fitting. Now they cost between eighty and one hundred
pounds.
The output peaks at a number of wavelengths making them suitable for all the
alternative processes I use from platinum to carbon.
I am sure that there must be a US manufacturer of these things. If not Philips,
which is a big international, is hardly likely to give the US a miss with its
products.
Terry