Vibrating Wire Strain Gauge

Overview

RST Vibrating Wire Strain Gauges are designed to be welded to or embedded in various structures for monitoring strain. RST vibrating wire strain gauges are available in 3 models: VWSG-A, for arc welding to steel structures; VWSG-S, for spot welding to steel structures and VWSG-E for embedment in concrete.

Each strain gauge consists of two end blocks (designed specifically for each application) with a tensioned steel wire between them. As the steel or concrete surface that encompasses the strain gauge undergoes strain, the end blocks will move relative to each other. The tension in the wire between the blocks will change accordingly, thus altering the resonant frequency of the wire. A vibrating wire readout is utilized to generate voltage pulses in the magnet/coil assembly located at the center of the strain gauge. The magnet/coil assembly plucks the wire and measures the resulting resonant frequency of vibration.

The advantages of vibrating wire strain gauges are that the frequency output is immune to electrical noise, able to tolerate wet wiring common to geotechnical applications, and capable of signal transmission of several kilometers without loss of signal.

RSTAR Affinity Data Loggers, DT Series Data Loggers, or the RST VW2106 Vibrating Wire Readout, (see separate brochures) can be used to read vibrating wire strain gauges.