Vibrating wire displacement sensors are currently a type of non-electrical quantity measurement sensor that is widely valued and applied both at home and abroad. It consists of a heat-treated vibrating wire detection element, a stress-relieved spring with one end connected to the vibrating wire and the other end connected to the sliding pull rod. As the sliding pull rod is pulled, the spring begins to elongate and causes an increase in the tension of the vibrating string. The vibration frequency of the steel string also changes accordingly. The tension is directly proportional to the elongation of the spring. Therefore, the change in displacement can be achieved by measuring the tension of the steel string, that is, the change in the vibration frequency of the steel string.
It has the following advantages when applied to tunnels:
1. Strong anti-interference ability: Frequency signal transmission is not sensitive to changes in cable length and resistance, and is less affected by electromagnetic interference.
2. Good long-term stability: Strong anti-interference ability, less affected by electrical parameters, small zero drift, less affected by temperature, stable and reliable performance, shock-resistant, and long service life.
3. Absolute measurement: The measured value represents frequency and is an absolute quantity. There is no need to worry about data loss after power failure.
4. Adaptability to harsh environments: Moisture-resistant, dust-proof, and corrosion-resistant, capable of withstanding the high humidity, dust, and chemical substances inside tunnels.
It is also an important component of the tunnel engineering monitoring system, playing the role of a sentry, preventing accidents, protecting life and property safety, avoiding catastrophic maintenance, achieving preventive maintenance, reducing the total life cycle cost, and through scientific maintenance, extending the service life of the tunnel and realizing the intelligent management upgrade of tunnel operation and maintenance from "experience-driven" to "data-driven". Therefore, In modern tunnel engineering, especially in long tunnels, important traffic trunk tunnels and urban subway tunnels, vibrating wire displacement sensors have become indispensable key monitoring equipment.
Vibrating wire displacement sensors are also widely used in various fields. They are extensively applied in buildings, DAMS, Bridges, rocks, concrete, soil, roads, factories, and other engineering projects to monitor the displacement, settlement, deformation, cracks, etc. of structural objects, and to conduct long-term relative displacement change monitoring.
