Claude Seymour
On Thu, 18 Aug 1994, Philip Jackson wrote:
> I've put together a bank of 4 NEC 20 watt blacklight flouro tubes, which
> aren't too bad for cyanotype (about 20 min at about 10 cm. vs 8 min with
> the sun), but are pretty hopeless when it comes to exposing a thick layer
> of wet dichromated gelatin for the woodburytype process. I gave up after
> 14 hours!
>
> A used platemaker with metal halide bulb is probably ideal. Do they put
> out much heat though? The next best thing after that is probably the sun.
> Other options I've looked at but not used:
>
> 1. Printed circuit board exposure units. The Ultra-lite max manufactured
> by Logical Devices of Ft Lauderdale has 4 UV elements, a tray size of
> 9" x 13" and is supposed to put out 1500 micro watts per square centimetre.
> I'm not sure of the wavelength or how it compares to normal BL tubes.
> Price here is Aust $450. EPROM erasers are much cheaper but wouldn't
> have much coverage.
>
> 2. High intensity UV inspection lamps. The Spectroline MB-100 gives a
> concentrated beam of 365 nm with 4,400 micro watts/cm2 at a distance of 15
> inches, but must have a very narrow beam of about 7 inches. There's also a
> flood bulb which gives 1,100 microW/cm2 (coverage unspecified). Price here
> is Aust $900.
>
> Philip Jackson
> pjackson@nla.gov.au
>
>