Has anyone tried to pressurize an underwater housing, to reduce the stress on the seals? If so, did the air come off the SCUBA tank via the octopus; or was it supplied by a small, dedicated bottle, with, say, moisture-free nitrogen? Of course, one would need an automatic bleed-off valve for the ascent, yada yada yada...
It would seem that having a small pressure regulator to keep the air inside the housing just a few inches WC above the pressure of the surrounding water would make life easier.
The analogy would be a conventional camera housing is to helmet diving as a pressurized camera housing is to SCUBA diving.
[PS: Many years ago at Scott Paper, when we had to install a motor control center or instrument cabinet in a wet (& lightly corrosive at times) location, we would pump dried instrument air into the cabinet to about an inch or so of pressure to keep the outside atmosphere, well, outside.]
Edited by Dan Schwartz, 17 October 2007 - 08:12 AM.