Examine Strain Movements with Vibrating Wire Strain Gauge

Instruments used to check the short and long term strains on tunnel linings, arches, piles, struts, dams, rock surfaces and many other such structures are called vibrating wire strain gauge. The device comes with a tensioned steel wire enclosed in a stainless steel tube. The steel wire is supported by two blocks at the two ends.  Electromagnetic coils located close to the wire when excited induce the wire to swerve at high speed.

The wire sways for a certain time creating an alternate current output. The frequency in the output is detected and fixed by a readout unit supported by a vibrating wire interface converting it into units of strain. The two blocks change their position due to the changes in the tension of the wire within the gauge. This results in change in resonant frequency of swerving of the wire. The device comes in different types to suit various applications like embedment type, surface mount, sister bar and spot weld type.

Conversion of fluid pressures in standpipes, boreholes, embankments, pipelines and pressure vessels are done by vibrating wire piezometers.  It is used for understanding the nature of the site, predict slope stability, check the safe rate for placing the fill and evaluate effectiveness of drainage schemes. These instruments are available in different models to suit various needs.