Piezometer Monitoring
Piezometer Monitoring measures pore water pressure and groundwater levels. It supports the assessment of slope stability, seepage control, and foundation performance in embankments, retaining walls, tunnels, and dams.
Category
VW Piezometer
(Electric Frequency)
FBG Piezometer
(Light Wavelength)
Mechanism
Water pressure pushes against a stainless steel diaphragm, causing it to deflect. This change in deflection alters the tension of a wire attached to the diaphragm.
Similar to the VW piezometer, water pressure deflects a diaphragm. However, instead of a wire, an optical fiber with a Fiber Bragg Grating is attached to the diaphragm.
Reading Method
An electromagnetic coil “plucks” the wire, and the frequency at which it vibrates is measured. This frequency is then converted into a pressure reading (kPa or psi).
Light is sent down the fiber. As the diaphragm moves, it stretches the grating, changing the wavelength of the reflected light. An optical interrogator measures this “wavelength shift.”
Data Speed
Static / Low Frequency
High-speed Dynamic (up to 5kHz)
Best For
Automated data acquisition (SDAU/RTU systems), deep installations, and projects requiring high reliability in harsh environments.
Infrastructure with high EMI (like railways), areas prone to lightning, or when monitoring hundreds of sensors on a single fiber line.
