SISGEO Vibrating Wire Strain Gauges range provide multiple options for measuring strain in concrete and steel structures.
The instruments incorporate a tensioned wire that, when excited with an electromagnet, alters its fundamental frequency which is picked up with the readout or data logging unit. For steel structures weldable anchors transfer the strain onto the wire and in reinforced concrete, gauges are embedded into the concrete directly.
These VW strain gauges can be read manually with a vibrating wire readout, or logged automatically with our range of data logging systems. The reading from the gauges is easily converted into micro-strain and is can be installed in a rosette to compensate for any eccentricity of loading.
- Uses proven and reliable Vibrating Wire technology
- Suitable for manual or remote reading
- Range is adjustable to suit compression or tension on arc weldable models
- Contains an integral thermistor for temperature monitoring and compensation
- O-ring seals provide waterprooﬁng
- Accurate, repeatable readings over long cable lengths
- Long working life, long term stability and reliability
- Robust and reliable
On the arc-weldable model the sensors are installed by arc welding two mounting blocks (using a setting bar as a template) onto the steel structure to be monitored. Once the welds have cooled the sensor can be fitted into the blocks and tensioned as necessary.
Embedment gauges are installed onto the reinforcement prior concrete pouring. The gauges can then be read immediately with a compatible readout or recorded automatically with a datalogger.
The readings from each instrument can then be converted into micro-strain by applying a calibration factor. Each gauge has an integrated thermistor by which temperature can be recorded alongside strain.
Arc-weldable model strain gauges are capable of recording changes in strain of steel or cast iron structural members, where embedment model gauges are suitable for direct embedment into reinforced concrete. Embedment model strain gauges are capable of recording changes in reinforced concrete structures.
Typical applications of the vibrating wire strain gauges include:
- Steel members and struts
- Excavation support systems
- Bridges and arches
- Tunnels and deep excavations
- Mass concrete pours
- Precast, driven and bored piles
- Retaining walls
- Building foundations
- Monitoring strain during construction, pile testing and service life.