Fully grouted installation permits multiple piezometers to be simply and reliably installed in a single borehole. The piezometer string and grout pipe are placed in the borehole and cement-bentonite grout is pumped until the borehole is filled.
Multi-point Piezometer Strings allow for multiple Vibrating Wire Piezometers to be connected on a single cable. This facilitates the installation of fully grouted multiple piezometers. The single cable prevents vertical void channels. Tough urethane jacketed, Kevlar® reinforced, non-stretch cable is employed to withstand the rigors of installation and is entirely water-blocked to minimize any leakage. No conductors are shared to maximize independent reliability of each sensor.
Vibrating Wire Piezometers provide excellent long-term accuracy, stability of readings and reliability under demanding geotechnical conditions. Vibrating Wire Piezometers are the electrical piezometers of choice as the frequency output of vibrating wire devices is immune to external electrical noise, and able to tolerate wet wiring common in geotechnical applications.
Traditionally, multiple piezometer installations in a borehole were slow, complex, and subject to unintended communication between piezometers. Grouted piezometers are quick and easy to install, have excellent zone isolation, and have rapid response to pore pressure changes. The fully grouted method is increasingly the preferred standard approach for installing piezometers in boreholes.
- Pressure range: 0,35, 0,7, 1,0, 2,0, 3,0, 5,0 7,0 & 10,0 MPa
- Over range: 2 x rated pressure
- Resolution: 0,025% FS minimum
- Accuracy: 0,1% FS
- Operating temperature: -20 to +80°C
- Diaphragm displacement: <0,001 cc at FS
- Thermal zero shift: <0,05% FS/°C
- Materials: Hermetically sealed stainless steel housing
- Thermistor type: NTC 3K Ohms @ 25°C
- Thermistor interchangeability: ±0,2°C (optional ±0,1°C )
- Thermistor resolution: 0,1°C
- Filter: 50 micron sintered (high air entry alumina filter 1, 3 or 5 Bar available)
- Connection dimension: 80 mm x 31 mm diameter
- Connector to piezometer cable (H): 200 mm
VW fully grouted, multi-point piezometers are custom built to suit specific applications. Provide the following information for the application:
- Number of piezometers
- Depth of/spacing between piezometers
- Pressure ranges
- Cable length to readout or data logger
- Total borehole depth
- Borehole diameter