Hydro adviser performs analysis and diagnostics for vibration and pulsation phenomena on the basis of suitable measurements, and recommends giving sufficient attention to this step. Quite often the root cause of a vibration problem is not evident at first glance, because there may be several possible causes. Actually, many different physical mechanisms may cause pulsation and vibration in hydropower machinery. In any troubleshooting campaign, remedial measures will be successful only if based on the proper explanation in the given case. This is why correct diagnostics is essential.
Recordings of sufficiently complete time series containing the pulsation phenomena with good resolution are crucial for successful analysis. Depending on the problem, both time-domain and frequency-domain methods of vibration analysis may be useful. Discrimination between various possible excitation mechanisms may use their different way of propagation; therefore a successful diagnosis often depends on evaluating relationships between the different signals.