Standard Borehole Piezometer

Standard Borehole Piezometer

Applications

The standard borehole piezometer is suitable for most applications. It can be directly grouted-in using a bentonite-cement grout. This greatly simplifies installation of multiple piezometers in the borehole and also allows the piezometer to be installed with inclinometer casing.

Custom cable lengths are available for all sensor ranges. Cable pricing will be provided on the formal quotation.

Standard Borehole Piezometer

Operation

The VW standard borehole 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.

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.

Standard Borehole Piezometer Specifications

STANDARD VW PIEZOMETERS
3.5 bar (50 psi) Piezometer 52611020
7 bar (100 psi) Piezometer 52611030
10 bar (150 psi) Piezometer 52611060
17 bar (250 psi) Piezometer 52611040
35 bar (500 psi) Piezometer 52611050
Signal Cable 50613824
VW PIEZOMETERS WITH CABLE
Standard VW Piezometers, 3.5 bar (50 psi) with 15 m (50') cable 52611028
with 30 m (100') cable 52611024
with 45 m (150') cable 52611027
with 60 m (200') cable 52611026
Standard VW Piezometers, 7 bar (100 psi) with 30 m (100') cable 52611033
with 45 m (150') cable 52611034
with 60 m (200') cable 52611035
with 90 m (300') cable 52611036

VW Piezometer Specifications

VW PIEZOMETER SPECIFICATIONS
Sensor Type Pluck-type vibrating wire sensor with built-in thermistor
Range Standard ranges are listed at left. Custom calibration ranges are available
Resolution 0.025%FS
Accuracy ±0.1% FS for 0.7 - 7 bar sensors, ±0.3% FS for 17 and 35 bar sensors
Maximum Pressure 1.5 x rated range
Filter 50-micron, sintered stainless steel. A ceramic 1-bar high-air entry filter can be ordered for standard and heavy-duty piezometers by specifying part number 60101240 in addition to the piezometer part number
Temperature Coefficient < 0.04% FS per °C
Materials Stainless steel
Size Standard: 19 x 195 mm (0.75 x 7.75")
Low-Pressure: 29 x 191 mm (1.125 x 7.5").
Heavy-Duty: 29 x 191 mm (1.125 x 7.5").
Push-In: 35 x 270 mm (1.385 x 10.5")
Weight Standard: 0.16 kg (0.3 lb).
Low-pressure: 0.45 kg (1 lb).
Heavy-Duty: 0.8 kg (1.75 lb).
Push-in: 1.2 kg (2.75 lb).

 

SIGNAL CABLE SPECIFICATIONS
Signal Cable 50613824 Shielded cable with four 22-gauge tinned-copper conductors and polyvinyl chloride (PVC) jacket
Armored Signal Cable 50613586 Shield cable with four 22-gauge tinned-copperconductors, inner polyurethane jacket, steel braid armor, and outer high-density, polyethylene jacket. For heavy duty piezometer only
READOUT & TERMINAL BOXES
VW Data Recorder 52613500
Jumper Cable for Terminal Box 52613557
Terminal Box for 6 sensors 57711606
Terminal Box for 12 Sensors 57711600
Terminal Box for 24 Sensors 97711624
DATA LOGGERS
VW MiniLogger for 1 Sensor 52613310
4-Channel V-Logger 52615140
Campbell Scientific Data Loggers