A Low-Cost Optical Sensor for Noncontact Vibration Measurements

This paper presents a new noncontact method to measure vibrations by using a low-cost optical approach that is able to provide a submicrometer resolution. The transducer exploits a simple optical setup based on an intensity-detection scheme that is implemented with plastic optical fibers, whereas innovative non demanding spectral data processing allows compensation of the vibrating surface reflectivity and the gains of the measurement chain. The performance of the proposed system has been assessed, through comparison with other techniques, by performing several measurement tests that use targets vibrating at frequencies from a few hertz up to several tens of kilohertz and with different values of reflectivity.