Strain gauges, to be spot welded or embedded in concrete, are used for the measurement of strains caused by force applied (strain) to concrete, iron beams, reinforcement cages, piles and other. Measurements provided are in microstrain which is the ratio of the strain measured by the instrument at its measuring base.
Differences in use are as follows: the smaller spot weldable sensor offers greater resolution and sensitivity of measurement, having a base of approximately 50 mm, compared to our vibrating wire strain gauge with a base of 150 mm (to be welded to beams, embedded in concrete or fixed to walls with the appropriate bolts).
Spot weldable strain gauges are generally used for the measurement of deformation/strain on load bearing metal beams, or for the measurement of strain in pipelines such as gas, oil and similar, where the measurement of 3000µ# strain corresponds roughly to a deformation of a tenth and a half of a millimetre on a 50mm base. These devices offer great precision and high resolution.
Strain gauges with a 150 mm base are used particularly for the measurement of strain in concrete structures or reinforcement bars, where a measurement with accuracy of up to 4-5 tenths of a millimeter is indispensable, although providing measurements with a lesser precision and resolution than the above instrument.
Like all vibrating wire sensors, strain gauges guarantee great reliability over time, making them ideal for long-term monitoring systems.
These instruments are able to measure the temperature and compensate measurements obtained, when necessary, for thermal variation.
The most common applications are: