Water Level Meter
A Water Level Meter is used to determine the water level within a borehole, piezometer pipe or sump.
It consists of a stainless steel shrouded probe with a specially designed conductive probe to minimise displacement errors, providing unparalleled accuracy particularly in small bore piezometers.
As the probe is lowered into the water, a single audible buzz is heard and a red light shows.
It is mounted on a rugged lightweight drum with integral brake and probe holder for easy operation and storage.
Vibrating Wire Piezometers
Geosense® VWP-3000 Series of Vibrating Wire piezometers use the well-proven method of converting fluid pressures on a sensitive diaphragm into a frequency signal.
Frequency signals are particularly suitable for the demanding environment of Civil Engineering applications, since the signals are capable of long transmission distances without degradation, tolerant of wet wiring conditions and resistant to external electrical noise.
Key applications include measuring pore pressure in soils and rocks and fluid pressures in hydro-fractures and pump tests.
Models in the VWP-3000 range are:
- VWP-3000 (STANDARD) Standard construction with high & low air entry filters to measure groundwater elevations and pore pressures.
- VWP-3310 (STANDARD VENTED) Standard construction but vented to compensate for barometric pressure changes. Available with high & low air entry filters.
- VWP-3100 (HEAVY DUTY) Heavy duty body for direct burial in fills and dam embankments. Available with high & low air entry filters, standard and heavy duty cable.
- VWP-3200 (LOW PRESSURE) Low pressure version to measure groundwater elevations and pore pressures. Available with high & low air entry filters.
- VWP-3300 (LOW PRESSURE VENTED) Low pressure vented version to compensate for barometric pressure changes. Available with high & low air entry filters.
- VWP-3400 (DRIVE-IN) Drive-in version available for use with SPT rods.
- VWP-3401 (DRIVE-IN) Drive-in version available for use with 1” BSP adaptor.
Strain Gauge Piezometer
The Geosense® SGP-3400 Series of strain gauge piezometers are designed for monitoring soil pore pressure or changes in water level and are also suitable for dynamic monitoring such as pumping tests.
They are accurate, highly-reliable and suitable for use in the harsh environments often found within civil engineering including water wells, boreholes, dams, reservoirs, rivers, tanks or any other body of water.
The sensor is housed in a robust stainless steel sealed body with a porous filter tip, which are available in different porosities to suit specific site conditions.
It comprises a highly sensitive stainless steel diaphragm onto which a Wheatstone bridge strain gauge is mounted and connected to a signal-conditioning board to convert to a 4-20mA output within the piezometer housing.
When liquid pressure is applied to the diaphragm it causes the Wheatstone bridge strain gauge to output a signal, which is directly proportional to the applied pressure.
They are available in standard or vented versions and can be read by simple hand held readout units or integrated into a data logger for fully automated monitoring.
Multi-Point VW Piezometer
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 rigours 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.
Standpipe Piezometer
Simple and economic measurement of groundwater pressures in soil and rock can be carried out using Casagrande type piezometers.
Geosense® piezometers are made up of low air entry porous plastic or ceramic elements which are connected to standpipe tubing and lowered into a predrilled borehole. Alternative types may be driven or pushed into soft soil.
Where Casagrande type piezometers are being installed then the porous element is surrounded by filter sand and a Bentonite seal placed above this response zone.
Water level measurements are normally taken using a water level meter (dip meter) or in the case of artesian pressure a Bourdon pressure gauge is attached to the top.
VW Pressure Transducer
The Geosense® VWT-9000 Series of Pressure Transducers are designed to be connected directly into hydraulic or pneumatic pressure lines by means of a 1/4” BSPF thread. Other thread sizes are available on request.
They are typically used to monitor uplift pressures within dams and to enable manual standpipe piezometers to be upgraded into an automated data acquisition system.
They are accurate, highly-reliable and suitable for use in the harsh environments often found within civil engineering including water wells, boreholes, dams, reservoirs, rivers, tanks or any other body of water.
Vibrating Wire technology is a well-proven method of converting fluid pressures on a sensitive diaphragm into a frequency signal which is capable of long transmission distances without degradation, tolerant of wet wiring conditions and resistant to external electrical noise.