The working principle of optical fiber vibration displacemen
The working principle of the optical fiber vibration displacement sensor is shown in the figure below.
The light beam of the optical fiber displacement sensor includes the transmitting fiber and the receiving fiber. P0 and P1 in the figure are the transmitting and receiving light respectively. The measured target has the property of diffuse reflection. The received reflected light is converted into a voltage output. With the increase of the cone trace overlap between P0 and P1 and the target, the output voltage curve with respect to displacement z tends to rise. After reaching the peak light, with the increase of displacement z, the output voltage decreases according to the inverse square law.
2) Reflection compensation fiber probe. If the reflectance of the target to be measured has a large change, an automatic compensation type of probe can be used. The probe of this structure can maintain high resolution and accuracy in the dynamic reflectance range of 100∶1.
One beam transmits, the other two receive, and have different response characteristics. According to the electronic principle of the probe module, the signal difference between the two receiving fiber bundles is used to compensate the reflectivity change, and the linear response proportional to the probe gap is obtained. This probe can be used in the translation or rotation state of the target.
