Vibrating wire piezometers are strongly recommended for long term monitoring of soil pore pressure or ground water levels.
The VW piezometer consists of a stainless steel body equipped with a filter unit (porous stone) and a pressure sensitive diaphragm with tensioned steel wire. The vibrating wire is tensioned inside an hermetically sealed and vacuum space.
VW piezometers guarantee fast response, long-term stability and immunity to voltage surges (lightning). Readings of VW piezometers are obtained by vibrating wire readout or datalogger.
Filter units are available with different porosity: either HAE (high air entry) and LAE (low air entry) value filters are suitable for piezometer applications in impervious, satured and permeable soils.

Technical specifications

Model PK45A    With HAE value filter unit
Model PK45S    With LAE value filter unit
Model PK45I    Drive-in version to be pushed into a soft soil by push-in rods
Standard ranges    200, 350, 500, 700 kPa
1.0, 1.7, 2.0, 3.5 MPa
Sensitivity    ±0.025% FS
Accuracy    ˂0.5% FS
Temp. operating range    -200C +1000C
Filter unit features
-HAE (100kPa)
-LAE stone    
1µ ceramic stone
40µ syntherized s/steel
40/50µ syntherized PE
Diameter/length    27 mm/200 mm

SATURATION DEVICE
The filter saturation is a decisive factor of a successful installation of embedded piezometers..