Diffused Air Flushing

GCTS Diffused-Air Flushing Device is an accessory designed to eliminate diffused air bubbles formed beneath ceramic plates during unsaturated soil testing such as triaxial, direct shear, and SWCC.

The water expelled or absorbed by a soil specimen during testing migrates through the ceramic stone installed at the bottom of the specimen. Due to diffusion, a small amount of air also passes through the stone depending on the applied suction and the duration of the test. To obtain an accurate measurement of water expelled or absorbed, the diffused air should be flushed out of the system.

GCTS Diffused-Air Flushing device is connected to the bottom of the ceramic stone via a computer-controlled ball valve. A water level sensor is attached to the bottom of the device. Air flushing is performed by opening the ball valve and moving sufficient amount of water. Then the water level is brought back to the original level by the pressure/volume controller. The new position of the pressure/volume controller gives the amount of migrated water. Note that the water level in the flushing device is used as a reference only, and it does not provide any water volume information.

Economically priced units with manual valves and level indicators are also available.