Pressure Cells
Borehole Pressure Cells
The standard Borehole Pressure Cell (BPC) is used to measure rock stress changes and is designed to be grouted inside a borehole. The BPC is manufactured from two steel plates welded together around their periphery. The plates are deformed into a “dog bone” configuration (i.e. the borehole flatjack) so that they can be expanded easily, without damage to the welds. Hydraulic oil fills the space between the two plates and a high-pressure stainless steel tube connects the plates to a stainless steel pressure gauge and/or a pressure transducer.
| Specifications | |
|---|---|
| Standard Ranges | 20, 35, 75 MPa |
| Resolution | 0.25% of range (approximately) |
| Accuracy | 0.25% F.S. (gauge); 0.1% F.S. (VW transducer) |
| Borehole Size | 57 mm |
| Temperature Range | −20°C to +80°C |
| L × W × H | 203 × 47.6 × 12.7 mm (borehole flatjack only) 508 × 47.6 × 12.7 mm (borehole flatjack with stainless steel tube) |