Displacement measurement technique using fiber optic sensors

A new technique of displacement measure-ment using fiber optic sensors is brought up in this paper It is composed of three parts, which are the fiber optic sensor, the circuit of displacement measurement and computer By the appropriative software, it can measure the displacement and display it in real time. This paper in brief introduces their operation principles. In order to avoid using expensive optical system, reduce the complexity in debugging, we choose the intensity modulation type of fiber optic sensors, whose structure is simple and reliable. There are two schemes, one is the mask type and the other is the reflective type. Pie reflective type can be used in uncontacted test, but it has much shortcoming on. our condition. For example, high quality is asked for the material and curvature of reflective plane, the sensor suffers from the interference of background light, manufacture of probe is complicated, we need to design the appropriative holder in test, the span is only about 100mum, to extend the dynamic range we must increase a set of optical lens on the end of optic fiber, but consumedly increase the probes volume. Because of all above reason, the possibility of this kind of method applied to actual work is little. So on the basis of the mask type of transducers, using fiber optic bind to improve the bad linearity greatly because of gauss distribution of light field on fiber end, we design a new mask type of fiber optic sensor Structure of sensors is compact, debugging of system is simple, meanwhile span is large and linearity is good, as well as anti-interference is strong verified by calibration.