The principle of vibrating wire sensors in measuring the changes of wall cracks is to convert the opening and closing displacement of cracks into changes in the tension of steel strings, and then map them into precisely measurable vibration frequency signals, achieving long-term and anti-interference monitoring of millimeter-level crack widths.
Application measurement installation method:
The two ends of the sensor are anchored on both sides of the crack. When the crack widens, the internal sliding pull rod is stretched, driving the spring to elongate and reducing the tension of the metal vibrating wire. Conversely, when the crack closes, the tension increases.
Vibrating wire sensors are currently a type of non-electrical quantity measurement sensor that is widely valued and applied in China. It has a unique mechanical structure form and the magnitude of the force is characterized by the change in the vibrating string frequency. Therefore, it has the performance of long-term zero stability and can directly output as a frequency signal. It has strong anti-interference ability and is less affected by electrical parameters. Compared with the resistance strain gauge with analog output, it can more simply and conveniently collect, transmit, process and store data. Achieve high-precision automatic testing. It is a highly stable sensor specifically designed in civil engineering for monitoring the minute opening and closing deformations of structural surfaces or joints, and is widely applied in scenarios such as DAMS, Bridges, tunnels, and concrete buildings. Its core value lies in: not relying on the stability of external power supply, not being affected by cable length, and having extremely small long-term zero drift, making it particularly suitable for long-term unattended field monitoring.