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 the 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 on 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) Piezometer52611020
7 bar (100 psi) Piezometer52611030
10 bar (150 psi) Piezometer52611060
17 bar (250 psi) Piezometer52611040
35 bar (500 psi) Piezometer52611050
Signal Cable50613824
VW PIEZOMETERS WITH CABLE
Standard VW Piezometers, 3.5 bar (50 psi)with 15 m (50') cable52611028
with 30 m (100') cable52611024
with 45 m (150') cable52611027
with 60 m (200') cable52611026
Standard VW Piezometers, 7 bar (100 psi)with 30 m (100') cable52611033
with 45 m (150') cable52611034
with 60 m (200') cable52611035
with 90 m (300') cable52611036

VW Piezometer Specifications

VW PIEZOMETER SPECIFICATION Sensor
r TypePluck-type vibrating wire sensor with built-in thermistor
RangeStandard ranges are listed at left. Custom calibration ranges are available
Resolution0.025%FS
Accuracy±0.1% FS for 0.7 - 7 bar sensors, ±0.3% FS for 17 and 35 bar sensors
Maximum Pressure1.5 x rated range
Filter50-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
MaterialsStainless steel
SizeStandard: 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")
WeightStandard: 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 Cable50613824Shielded cable with four 22-gauge tinned-copper conductors and polyvinyl chloride (PVC) jacket
Armored Signal Cable50613586Shield cable with four 22-gauge tinned-copper conductors, inner polyurethane jacket, steel braid armor, and outer high-density, polyethylene jacket. For heavy-duty piezometer only
READOUT & TERMINAL BOXES
VW Data Recorder52613500
Jumper Cable for Terminal Box52613557
Terminal Box for 6 sensors57711606
Terminal Box for 12 Sensors57711600
Terminal Box for 24 Sensors97711624
DATA LOGGERS
VW MiniLogger for 1 Sensor52613310
4-Channel V-Logger52615140
Campbell Scientific Data Loggers