Which of the following is a key characteristic measured in vibration analysis?

Frequency is a crucial characteristic measured in vibration analysis, as it indicates how often a vibration occurs within a specific time period. This measurement is essential for diagnosing machinery conditions and identifying anomalies. Vibration frequencies can reveal information about the operational state of the equipment, such as indicating potential misalignments, imbalances, or resonance issues.

In vibration analysis, frequency is often used in conjunction with amplitude and velocity to form a comprehensive understanding of the machinery's performance. While amplitude measures the size of the vibration, and velocity gauges how fast the vibration is occurring, frequency specifically addresses the repetition of vibration cycles, which is vital for troubleshooting and predictive maintenance strategies. Thus, understanding frequency helps technicians to pinpoint specific faults based on the signatures of vibrations related to different mechanical problems.