A Low Cost Optical Sensor for Non Contact Vibration Measurements

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