Vibrating Wire Piezometer - VWP

How it works

The sensing element is a steel wire clamped to both ends of a hollow cylindrical body. An electromagnetic coil excites the wire and measures its vibration period, which is sensitive to the pressure applied to the sensing element. The wire is clamped using a proven hydraulic swaging technique for high stability, and the sensing element is hermetically sealed to protect the steel wire against corrosion; all parts other than the wire itself are machined from high-grade stainless steel. The PW is fitted with a surge protector and resists electrical and radio frequency interference, tested to IEEE and CEI specifications.

Model variants

PWS: designed for embedding in earth fills, at concrete/earth interfaces, or insertion into boreholes and small-diameter pipes; fitted with a removable high or low air entry filter that protects the sensing element from solid particles.

PWF: a thick-walled version of the PWS for direct burial applications.

PWC: fitted with a pipe thread adapter, allowing use as a pressure transducer.

PWP: designed to be driven into unconsolidated fine-grain materials such as sand, silt or clay, with a thick-wall cylinder housing fitted with a conical shoe and an EW drill rod or standpipe thread adapter.

PWL: a low-pressure piezometer (35, 70 kPa).