Vacuum reservoir operating pressure can be adjusted between 2.0 kpa and 20 kpa necessary.
Water is supplied from the ground , the velocity of water over a period of 15 min adjusted to keep the specimen in water.
Water into the vacuum reservoir while maintaining the vacuum and can be used also .
The pressure in the vacuum container can be adjusted to remain constant for 24 hours when the reservoir reaches the desired level of pressure in the low pressure swithc.