On the effectiveness of standards application to threshold setting in vibration condition monitoring in industrial machinery

One of the goals of Industry 4.0 is to minimize unplanned maintenance emergencies and to leverage the efficiency of condition-based, just-in-time labor and repairs. Achieving the benefits of predictive maintenance via an Industry 4.0-style plant requires not only a data capture ecosystem, but also reference values to inform the monitoring system. Effectively estimating the values of monitoring thresholds is not an easy task, especially in those cases where the manufacturer does not provide data, or the machine is not new but the monitoring system has just been installed, therefore a measurement history is not yet available. The purpose of the present work is assess, through the analysis of two separate test cases, whether the monitoring thresholds suggested by different internationally recognized standards may serve as effective starting values in a vibration-based condition monitoring system. While general agreement on the order of magnitude of the thresholds is present in all cases, the differences between the standards allow for conclusions to be drawn on the most convenient format and processing technique to handle the data and to assess the most/least conservative standards. This paper constitutes, to the authors knowledge, the only systematic study in which the recommendations of all available international standards for vibration monitoring of non-rotating parts are applied to the same test cases and compared.