In addition to accelerometers, what practice is used to assess rotational vibration over time?

• A. Real-time thermography.
• B. Acoustic emission monitoring only.
• C. Visual inspection of components.
• D. Periodic trend analysis of vibration data.

Answer: (D)

Tracking how vibration evolves over time relies on turning the accelerometer readings into a history you can compare against a baseline. By periodically collecting vibration data and analyzing trends, you see whether levels are creeping up, if the dominant frequencies are shifting, or if the overall vibration pattern is changing. This long-term view makes it possible to catch gradual deterioration from issues like bearing wear, misalignment, imbalance, or looseness before a failure occurs. Other techniques focus on instantaneous conditions, temperature maps, transient events, or visual condition without providing the same clear picture of how vibration behavior develops over time.