Roctest FPC-2 Pneumatic Piezometer

The FPC-2 Pneumatic Piezometer is designed to measure fluid pressure in soil and rock masses and at the interfaces or in the vicinity of structures buried in the ground. It is used to monitor pore-water or joint-water pressure in:

  • Embankments and backfills
  • Dams
  • Foundations (seepage and uplift)
  • Natural and cut slopes
  • Excavations
  • Retaining walls, piles, culverts and tunnel linings
  • Waste disposal sites

Close block

The cylindrically-shaped FPC-2 Piezometer is fitted with a filter at its base and has two pneumatic-tubing fittings to connect the nitrogen gas input and return lines (nylon type 1 or polyethylene).

The FPC-2 consists of a thin flexible diaphragm on which the fluid pressure is applied. During readout this pressure is balanced by externally applied nitrogen gas pressure. The readings are obtained when the external gas pressure is equal to the pore-water pressure acting on the reverse side of the diaphragm. The volume change associated with pressurization of the diaphragm is extremely small and consequently the response time is very low, even in low permeability soils as clays.

The design and the materials (stainless steel or brass) used in the construction of the FPC-2 make it particularly suitable for use in both short and long term monitoring programs where ruggedness, stability and reliability are required. An integrated filter on the input gas line

Two models are available:

  • Model FPC-2 for borehole installation
  • Model FPC-2D to be pushed in place


  • High resolution and accuracy
  • Short response time
  • Highly reliable
  • Excellent stability
  • Negligible displacement of the diaphragm
  • Available in brass or stainless steel
  • Quick-release connectors available