Pore pressure sensor
A high precision sensor
Piezometers are used in engineering and geotechnical applications to monitor water levels and pore pressures.
The piezometer contains a membrane that deforms with the water pressure, causing a variation in the electrical signal measured with the THMLogger.
We distinguish two types of sensor, the first is a vibrating string and the second is a piezoresistive.
In the piezometers with vibrating string (VW) the deformation of the membrane causes the tension of a steel wire stretched between the body of the sensor and the membrane to vary, which results in a variation of the resonance frequency.
In the resistive model, strain gauges are printed on a ceramic membrane and glazed into the ceramic body of the sensor.
These strain gauges change their resistance and de facto the electrical signal proportionally to the deformations induced by the water pressure on the membrane.
The piezometer allows to :
- Follow the water table levels.
- Follow the pressure.
- To carry out a follow-up of temperature control.