A VACUUM CHAMBER is a rigid enclosure from which air and other gases are removed by a vacuum pump. The resulting low pressure, commonly referred to as a vacuum, allows researchers to conduct physical experiments or to test mechanical devices which must operate in outer space (for example). Chambers made of aluminum allow one to control the magnetic field inside from outside the vacuum. At the opposite chambers made of mu-metal prevent external fields from entering the vacuum. Chambers often have multiple ports, covered with vacuum flanges, to allow instruments or windows to be installed in the walls of the chamber. In low to medium-vacuum applications, these are sealed with rubber o-rings. In higher vacuum applications, the flanges have hardened steel knives welded onto them, which cut into a copper gasket when the flange is bolted on. wikepedia.org

This is the final step after taking all those photos of gradually getting dress and adding gear. I'm fully dressed in my U.S. Divers Aqualung 7mm wetsuit and I've put the BCD over my shoulders and strapped on all the extra gear. The valve is closed on my Interspiro mask and the tank is turned on making me breathe the tanks compressed air. Just a short trip to water and I'm scuba diving.