LimeyGreg (Jul 11, 2001 08:43 p.m.):
Yes, vacuum oven. I repair flexible endoscopes, when I have the time, as a side job. They contain fiberoptic bundles for both light and vision as well as cables and wires. When a fluid invasion occurs it needs to be removed, not an easy task on a sheathed bundle of umpteen thousand fibers.
The oven runs at a fairly low temperature and the vacuum helps pull the moisture from the bundle as well as reducing it's evaporation point. The vacuum is cycled several times during the process and a final purge is done with helium (hygroscopic). It basically speeds up the drying process and helps minimize the staining that can occur in the image bundle during a lengthy drying period.
It's also useful for de-gassing adhesives and coatings prior to application. Another use is in mould making to remove bubbles from the casting and to accelerate curing.