Benchmarking of a Cost-effective Micro-Interferometer for Remote Vibration Monitoring

A low-cost and low-size interferometer, based on self-mixing interferometry, has been developed for replacing standard accelerometers. The structure of the micro-interferometer is described in detail, and its measurement performances are evaluated with particular reference to preventive diagnosis of mechanical systems. For this purpose, a test bench equipped with accelerometers was used, on which intact or damaged ball bearings can be mounted. In the experimental tests carried out, the micro-interferometer showed signiAicantly superior performance to accelerometers in reporting faulty behaviour of the mechanical structure.