What action should you take if you see low amplitude, non-synchronous peaks in an envelope spectrum?

When you observe low amplitude, non-synchronous peaks in an envelope spectrum, the most appropriate action is to continue monitoring the machine while checking the spectra and time waveforms. This approach is critical because low amplitude peaks can indicate subtle issues that may not require immediate action but still need careful observation.

Monitoring allows for a better understanding of the machine's condition over time, as trends can emerge that may signal a developing fault that requires attention. Additionally, analyzing both the envelope spectrum and the time waveform can provide deeper insight into the behavior of the machine, helping to identify patterns or changes in vibration that could signify early stages of wear or malfunction.

In contrast, immediate actions like scheduling bearing replacement, checking for gear faults, or looking for rotating looseness may not be warranted based solely on low amplitude, non-synchronous peaks. Such actions can be more appropriate if there are clear indicators of specific faults rather than vague or weak signals. Thus, the best course of action is one of ongoing surveillance and assessment, maintaining the machine's efficiency and preventing unnecessary maintenance interventions.