Dec 15 2010
Developer of high-precision sensors, Roctest has introduced a new fiber-optic piezometer that delivers better performance when compared to conventional piezometers.
The FOP-MicroPZ piezometer has a length of 54 mm and a diameter of 4.8 mm and can be utilized in places where other piezometers cannot be used. The FOP-MicroPZ can be integrated with geotextiles and can be deployed in small-diameter standpipes.
FOP-MicroPZ Piezometer
The design of the piezometer is based on the Micro Optical Mechanical System pressure sensor’s non-contact deflection measurement. The pressure sensor features a versatile diaphragm that is assembled on top of the vacuum cavity. Fabry-Pérot’s white-light interferometry is used for measuring the pressure.
The pressure generates a difference in the Fabry-Pérot cavity’s length. The cavity consists of a reference optical surface on one side and the inner surface of the versatile diaphragm on the other side. By utilizing white-light interferometer modules, the interrogation is carried out.
Dataloggers and fiber-optic readout devices can precisely and consistently measure the length of the cavity under all kinds of vibration, humidity and temperature. The FOP-MicroPZ piezometer offers reliable pressure measurements in demanding conditions. The robustness is ensured by the stainless steel filter and protection sleeve. The filter shields the sensing elements from solid particles.