Abstract: A fiber optic transducer is provided for use in remote monitoring of the position of mechanical devices, such as the position of valves used in the petroleum and chemical industries and the like. The fiber optic transducer includes a transducer frame supporting an optical fiber under conditions of predetermined bending and tension. Cam apparatus is coupled between a mechanical device to be monitored and a bending pin having a cylindrical surface bearing against the fiber to control further bending thereof in response to position changes of the mechanical device. Changes in light transmission through the fiber as a result of bending can be detected and correlated with the position of the mechanical device.