A simple fiber optic sensor for angle measurement

A simple fiber optic sensor for angle measurement is described in this paper. It is based on a fiber optic bundle, which is bifurcated (“Y” shape), having a semicylindrical disposition of the fibers in the common bundle. Based on test results that have been carried out on a test apparatus built for this specific purpose, a comparison is described between the metrological characteristics of this transducer when it is used whether as a linear displacement transducer or as an angular one. The paper shows that by means of a very simple optical head, easy to connect to the fiber bundle a simple but powerful angular sensor can be realized, to be used as a null or deflection transducer. Taking into account the experimental behaviour of the whole measuring chain, the metrological characteristics of this sensor have been discussed and in particular sensitivity, resolution, accuracy and effects of modifying and interfering inputs, especially of geometrical type. The measuring chain can be easily modified to measure linear displacements, but in this case the capability of this system, with particular reference to its compactness and handiness are not so adequately exploited