Displacement and Acceleration Measurements in Vibration Tests Using a Fiber Optic Sensor

This paper discusses the evaluation of displacements and accelerations from noncontact displacement measurements using a low-cost plastic fiber-optic sensor. Issues about sensor calibration in the presence of nonuniform targets, which is a situation occurring in many practical applications such as vibration tests of printed circuit board assemblies, are analyzed. Furthermore, a procedure to contemporaneously calibrate several optical sensors to allow mapping the vibration amplitude and acceleration distributions in a simple and low-cost way is also disclosed. The proposed calibration procedure is particularly effective since it requires just one reference accelerometer, which is actually already available in typical vibration test facilities. Experimental results obtained under real conditions during a sinusoidal vibration test are also provided.