Groundwater sensor for groundwater level and pore water pressure
A vibrating wire piezometer in the borehole measures water and pore water pressure with long-term stability and records the temperature inside the sensor as well. The readings reach the Infrasolute data platform via data logger and gateway.
- Vibrating wire technology
- Range 50 or 100 psi
- Stainless steel SUS316
Why the groundwater sensor
Water pressure in the ground, measured where it acts
Groundwater level and pore water pressure determine the stability of excavations, slopes and dams. The sensor sits in the borehole, in the soil layer that matters.
Water and pore water pressure
The sensor records changes in water pressure at different depths and in different soil layers. This shows whether the water pressures assumed in the design match reality.
Frequency as the signal
The sensor measures the vibration frequency of a steel wire. The frequency signal is stable over the long term and insensitive to long cable runs.
Inconel pressure element
The sensor core is encased in stainless steel and Inconel and mechanically locked. This ensures stable readings and a long service life.
Integrated temperature
A thermistor measures the temperature inside the sensor with a resolution of 0.1 °C. It is recorded with every reading.
Built for the borehole
SUS316 stainless steel housing, 50 µm sintered filter and a double-layer water seal at the cable entry. Operating temperature from −40 °C to +125 °C.
Readings with alerts
The readings are evaluated in the data platform. If the water pressure exceeds a limit value, the system raises an alarm automatically.
Technical data
Specifications at a glance
Every sensor comes with a calibration certificate containing the factors for the pressure calculation.
- Measuring principle
- Vibrating wire sensor
- Measured quantities
- Water and pore water pressure, temperature
- Measuring range
- PZ-1050: 50 psi (≈ 3.45 bar, 35.2 m water column); PZ-1100: 100 psi (≈ 6.89 bar, 70.3 m water column)
- Resolution
- 0.025 % of full scale
- Accuracy
- ± 0.1 % of full scale
- Overload capacity
- 150 % of the measuring range
- Temperature measurement
- Thermistor, 3 kΩ at 25 °C, resolution 0.1 °C
- Operating temperature
- −40 °C to +125 °C
- Design
- Stainless steel SUS316, Ø 20 × 115 mm, 50 µm sintered filter
- Readout
- VW handheld readout or data logger with vibrating wire input, 4-core cable
Operating principle
From water pressure to frequency
Inside the sensor, a steel wire is clamped firmly at both ends. Water pressure changes its tension and therefore the frequency at which it vibrates. The pressure is calculated from this frequency using the factors in the calibration certificate of the sensor.
- 01
Pressure acts
Water pressure passes through the sintered filter to the pressure element and changes the tension of the wire.
- 02
The wire vibrates
A magnetic coil excites the wire. It vibrates at its natural frequency, which depends on the wire tension.
- 03
Read the frequency
A data logger or readout unit measures the frequency and the resistance of the thermistor.
- 04
Calculate the pressure
The pressure is calculated with the calibration factors of the sensor and linked to limit values in the platform.
Applications
Where the groundwater sensor is used
Everything from a single source
From the monitoring concept to operation
The groundwater sensor is one building block of a well-designed monitoring system. On request, Infrasolute takes on concept, installation, operation and ongoing monitoring as a complete solution.
- 01
Concept
We plan measuring points, installation depths and filter horizons to suit the ground and the requirements.
Learn more - 02
Installation
We check every sensor before installation, place it in the borehole and backfill it properly.
Learn more - 03
Maintenance and operation
We operate data loggers and gateways and keep data acquisition reliable over the long term.
Learn more - 04
Monitoring and alerting
Limit values for water level and pore water pressure run through the defined alarm chain, around the clock.
Learn more
Matching solutions
The sensor as part of a solution
The sensor records the readings. How this becomes monitoring is explained on the solution page.
Groundwater monitoring
The solution behind it: monitor groundwater levels, pore water pressure and drawdown during construction, with alerts at limit values.
View solution
Geotechnical monitoring
Monitor the excavation, slope and surroundings by total station as well, in the same platform as the groundwater data.
View solutionGroundwater sensors for your project
Tell us about the ground, depth and task. We will suggest measuring points, measuring range and notification paths.
Benedikt Seuss 
Data platform
All readings on one platform
The sensors transmit their readings wirelessly to the data platform, where they are evaluated, documented and continuously checked against your thresholds.
- AI-assisted data analysis
- User-focused reporting
- Continuous evaluation
- Warning and alarm thresholds
- Alerts by email and text message
- Remote access around the clock
- AI-assisted data analysis Condition within limits
- User-focused reporting Report ready
- Alerting Thresholds monitored
Frequently asked questions about the groundwater sensor
What does the groundwater sensor measure?
Which measuring ranges are available?
How is the sensor installed?
How do the readings reach the platform?
Can the sensor be used with an existing data logger?
Project inquiry
Request the groundwater sensor
Tell us where groundwater level or pore water pressure should be monitored. We will get back to you with a proposal for measuring points, installation and notification paths.
+49 6742 8599600 DE +41 41 670 00 11 CH [email protected]