Relationship between displacement direction and voltage change of optical fiber sensor
Optical fiber sensor is a kind of sensor which uses optical fiber as sensing element and detects physical quantity through the change of optical fiber. Displacement sensing is one of the common applications in optical fiber sensors, and its principle is to measure displacement by measuring the change of optical fiber length. When the optical fiber sensor measures the displacement, by fixing the optical fiber on the measured object, the length of the optical fiber will change correspondingly when the measured object is displaced. This change can be detected by the transmission characteristics of light in optical fiber, and the displacement is usually obtained by detecting the change of optical fiber strength with optical fiber sensor. In optical fiber sensor, the relationship between displacement direction and voltage change can be determined according to the specific sensor type and measurement method. Generally speaking, the displacement measurement output signal of optical fiber sensor is usually a voltage signal or a current signal, and the relationship between the specific change direction and the displacement direction needs to be determined according to the specific sensor type and measurement method. In some optical fiber sensors, the direction of displacement is directly proportional to the direction of voltage change, that is, when the measured object is displaced, the output voltage changes at the same time, and the direction of change is the same as that of displacement. In other optical fiber sensors, the direction of displacement is inversely proportional to the direction of voltage change, that is, when the measured object is displaced, the direction of output voltage is opposite to the direction of displacement. It is necessary to determine the relationship between the displacement direction of optical fiber sensor and the voltage change according to the specific sensor model and application scenario.