Vibrating Wire Piezometers
VW Piezometer Applications
Typical applications for VW piezometers are:
- Monitoring pore water pressures to determine safe rates of fill or excavation.
- Monitoring pore water pressures to determine slope stability.
- Monitoring the effects of dewatering systems used for excavations.
- Monitoring the effects of ground improvement systems such as vertical drains and sand drains.
- Monitoring pore pressures to check the performance of earth fill dams and embankments.
- Monitoring pore pressures to check containment systems at land fills and tailings dams.
VW Piezometers Operation
The VW piezometer converts water pressure to a frequency signal via a diaphragm, a tensioned steel wire, and an electromagnetic coil. The piezometer is designed so that a change in pressure on the diaphragm causes a change in tension of the wire. When excited by the electromagnetic coil, the wire vibrates at its natural frequency. The vibration of the wire in the proximity of the coil generates a frequency signal that is transmitted to the readout device. The readout device processes the signal, applies calibration factors, and displays a reading in the required engineering unit.
Types of VW Piezometers
Advantages of Vibrating Wire Piezometers
High Resolution: VW piezometers provide a resolution of 0.025% of full scale.
High Accuracy: Slope Indicator’s automated, precision calibration system ensures that all VW piezometers meet or exceed their accuracy specifications.
Groutable: The VW piezometer can be directly grouted-in with a bentonite-cement grout. More information about the direct grout-in method can be found in the VW piezometer manual and in a technical note.
Rapid Response: VW piezometers offer rapid response to changes in pore water pressure, whether they are grouted in, pushed into cohesive soils, or embedded in a sand filter zone.
Reliable Signal Transmission: With properly shielded cable, signals from the VW piezometer can be transmitted long distances.
Temperature Measurement: All VW piezometers are equipped with a temperature sensor.
For more information
Please download the datasheet and manual for the VW Piezometer. These documents can be viewed and printed with Adobe Acrobat Reader. For more information about fully-grouted piezometers, please visit our Papers and References page.