Dehnungsaufnehmer und Temperaturaufnehmer

Strain gauges are widely used to monitor strain and stress in concrete, reinforced concrete and metal structures and supports. They are very important because with not expensive system, are able to read the stress (µε) in many point of the same structure: this means that with strain gauges the engineer is able to control the load applied to the structure, the distribution of the load, monitor if structure-stress is near to the yield point, etc.

With low costs involved, the designers and engineers retrieve results of the strain and stress (µε) in many points of the structure. Temperature gauges are important and monitored if thermal effects influence the structure deformations.

The most common applications are: Tunnels and underground works, Dams, Buildings as high rise structures , Foundations and pile testing, Bridges and viaducts, Deep excavation.

Strain gauges are available with both vibrating wire and resistive technology. Vibrating wire type strain gauges (VW), are used in most cases due to their ruggedness, long life function expectation and the possibility to run long cable lengths.

VW strain gauges are available in many different models:

• Embedment strain gauges for concrete structures;
• Arc-weldable strain gauges for metal structural elements.
• No-stress strain gauges;
• mini spot-weldable strain gauges for metal structural.

All vibrating wire strain gauges, as all other Sisgeo VW instruments, have built-in thermistor for temperature monitoring and, if needed, for thermal data correction.

Temperature gauges are housed within robust and waterproof body for direct concrete embedding or installation in harsh environmental conditions. Different measuring technology can be chosen to suit all monitoring targets: vibrating wire (VW), platinum RTD (PT-100) or thermistor sensors. VW type temperature probes are used if very long-term monitoring is required whereas RTD technology is recommended when high accuracy is requested. Thermistors are the good compromise solution between cost and performance.

Temperature measurement sensor strings with up to 16 measuring point are available for monitoring borehole thermal profiles (e.g. for ground freezing projects), for big concrete mass curing temperature monitoring in dams, landslide permafrost monitoring and other applications.