Event Analysis and Post-Processing Analysis
A time signal is measured and stored at an event trigger or fixed time intervals for later evaluation (post-processing analysis of the time signal) by a specialist. When a time signal is stored at a user-defined time interval before and after a fault has been detected, this is called event analysis. The raw signal can then be post-processed to find out what type of fault has been detected and its severity. A time signal can also be stored at fixed time intervals for machine health assessment. Post-processing analysis is generally done if the automatic condition monitoring measurements (process and frequency conditioned vibration measurements) that detected the fault do not contain enough diagnostic information for planning maintenance action ahead of time. The stored time signal can be opened at any time for time domain or vibration frequency analysis. Frequency analysis includes frequency spectrum, cepstrum, envelope analysis, vector and bandpass.