An intensiometric contactless vibration sensor with bundle optical fiber for real time vibration monitoring

Software Defined Doppler Radar as a Contactless Multipurpose Microwave Sensor for Vibrations Monitoring

“…The mentioned approaches allow for achieving good results [ 1 , 2 , 3 ], but being directly subject to mechanical stresses, the sensors are exposed to wear and thus to a progressive alteration during their operation time. Optical methods, implemented with optical fibers placed at small distance from the monitored items, allow for obtaining higher reliability [ 4 , 5 , 6 , 7 ], but similarly to the piezoelectric sensors, they generally offer operating bandwidths on the order of a few kHz [ 8 , 9 ], and require the use of sophisticated signal analyzers to obtain good resolutions in results.…”

Intensity modulation‐based fibre optic vibration sensor using an aperture within a proof mass

“…Various intensity modulation‐based fibre optic vibration sensors (FOVSs) were previously discussed and compared; extrinsic reflective intensity modulation types, cantilever beam types, and the other types [16–24]. The extrinsic reflective intensity modulation types usually employed the bundle optical fibre to illuminate the target and collect the back‐reflected light, which express the amplitude of target vibration.…”

“…The extrinsic reflective intensity modulation types usually employed the bundle optical fibre to illuminate the target and collect the back‐reflected light, which express the amplitude of target vibration. However, it is sensitive to the reflectivity of the vibration surface and to the gains of the measurement chain [16, 17]. In the cantilever beam types, the cantilever beam works as a mass‐spring structure housed in a sensor case.…”