The Rebar strain meter comprises of stainless steel element of suitable length welded or wieldable between two rebars to reach the required length. A vibrating wire sensor is provided and it is covered with a water proof cover with inbuilt two core shielded cable of required length or four core shielded cable where thermistor provision is required. This cable is connected to Model SME 2460-S portable readout unit or connected to datalogger.

These instruments provide the necessary excitation to pluck the vibrating wire element so that it vibrates at its resonant frequency. This frequency is then measured by the readout unit. Strain in the concrete causes the same strain in the rebar and a corresponding change in the resonant frequency of the vibrating wire. Each strain meter is individually calibrated at the factory so that the relationship between strain & frequency is known and presented as a calibration factor. Since the vibrating wire element is axially located the strain meter is not affected by bending moments.