They differ from the gas-tight in that they allow expanding gas to escape from the bottle during its trip to the surface. This feature is intended to prevent explosions. On board, gases are collected from these samples for further analysis on land. Also, samples of vent water will be analyzed by various chemical methods. Removal of gases is handled by our water chemist on board, Eric Olson, and is done through a vacuum system.
Water is pulled from the sampler to a sink by gravity and vacuum.
At this stage, the gases still carry water vapor, and must be directed to a minus 60 degree C vapor trap, where the water vapor is frozen and separates from the gas phase. The dry gas follows the vacuum to the bellow pump where it is manually compressed through another series of tubes and valves. The ampoules are labeled and stashed for transport back to land. If it works, they will use it Ordinary objects, strange uses. Note the collection of household items in the photo at left.