Hydraulic Pressure Cells
The hydraulic pressure cells are designed to measure stresses in shotcrete tunnel linings, contact pressures on structures, and stresses in rock
walls. The cell consists of two steel plates welded at the edges to form a cavity, which is then filled under vacuum with de-aired oil. A length of
high-pressure tubing connects the cavity of the cell to the pressure pad to the pressure transducer. To accommodate shrinkage of the concrete after curing, a repressuring device can be used to expand the cells and restore good contact.
| Model | PK45H MODEL | P252A MODEL |
|---|---|---|
| Model description | VW pressure transducer | piezo-resistive pressure transducer |
| Full scales (FS) | 0-350 kPa up to 0-20.0 MPa 0-50 psi up to 0-2900 psi |
0-200 kPa up to 0-20.0 MPa 0-29 psi up to 0-2900 psi |
| Sensitivity | 0.03% FS | 0.002% FS |
| Total accuracy | < ±0.25% FS < ±0.1% FS on request |
< ±0.20% FS (for 200kPa FS) < ±0.15% FS (all other FS) |
| Typical frequency range | 2250 - 3000 Hz | |
| Output signal | frequency | 4-20 mA current loop |
| Electrical supply | 12-24 VDC | |
| Operating temperature range | -20°C +80°C | -20°C +80°C |
| Transducer Material | stainless steel | stainless steel |
