Light exposure unit? what for?

[perudo]

Hello,
Out of curiosity, I picked up a "light exposure unit" for really cheap yesterday in a second hand shop.
The seller said it was for photography.
Basically it is a very heavy box with UV lamps and a vacuum system .
Some search in google, makes me think it is rather more a machine used for serigraphy, but I saw someone using it fir bichromate prints...
So, has anyone used such a unit? What could it be used for in photography?

 

[sevo]

Every print shop had one. Essentially it is a serigraphy screen/photolithography plate contact print unit - gum bichromate essentially being a serigraphy coating on paper, that is kind a extension of the former. They can be abused for any other process that can benefit from a contact print vacuum frame, if you substitute the lamps with something more suitable.

Warning: The UV lamps used are severely harmful to your skin and eyes, so don't expose yourself to their light. Smaller units are often self-contained with the lamps inside a closed box. If it is a bigger open system, wear protective goggles and cover all skin, or place it in a separate room or behind a light-proof curtain and control it from a external switch.