Encardio-Rite - Products | Jackout Pressure Cell

Encardio-rite model EPS-30/35V-J-F jack-out pressure cell is designed to measure the total stress i.e. the effective stress due to the soil together with the pore water pressure in the voids between soil grains. It is suitable for measuring static or slowly varying stresses only. The jack-out total pressure cell basically consists of a circular flat capsule, constructed from two stainless steel discs welded around the periphery. One of the discs is a thin flexible diaphragm of around 3 mm thickness. It is the active face and is installed flush with the soil. The other disc is a thick rigid plate of around 12 mm thickness. It is the inactive face and is installed on the concrete side through another thick support plate.

The circular flat capsule is concentrically electron beam welded to a specially designed Encardio-rite pressure transducer incorporating the latest vibrating wire technology to provide remote and digital readout. The pressure transducer has an inherently high sensitivity.The space between the pressure transducer, the diaphragm and the support plate is completely filled with a de-aired fluid by a special process that guarantees that almost all the air is excluded from the fluid.The space confining the hydraulic fluid is entirely metal. No 'O' rings are used, the external construction being welded. This helps in increasing the cell stiffness thus materially improving the performance of the cell.

To prevent uneven stress on the cell, the jack acts on the support plate, rather than directly on the cell. Care should be taken to have the sensitive surface of the cell absolutely flush with the soil at the concrete/soil interface. This is achieved by activating a hydraulic jack to keep the cell in position while the concrete is poured in. The hydraulic pressure on the jack is maintained somewhat higher than the stress generated by the freshly poured in concrete at the level at which the jack-out pressure cell is mounted. This will prevent the poured concrete from seeping into the soil and cell interface.

Specifications:

Model EPS-30/31/32/33/34/35V-J-F;
F = 125 or 200 mm specify

Range(kg/cm2) 5, 10, 20, 35, 50, specify

Temperature limit

Operational -20 to 70^oC

Compensated 0 to 55^oC

Over range limit 150 % of range

Over range effect ± 0.1 % fs up to 150 %

Overall dimension 125 mm F x 190 mm height

- 300 mm F x 190 mm height

Enclosure Stainless steel

Thermistor YSI 44005 or equivalent (3,000 Ohm at 25^oC)

Read out Portable strain indicator