What are the three categories for vibrations?

• A. Low, Medium and High
• B. Minor, Moderate and Severe
• C. Trivial, Moderate and Severe
• D. Slight, Moderate and High

Answer: (A)

Vibration levels are described using three terms to convey severity clearly and consistently: low, medium, and high. This scale provides a straightforward progression from normal or tolerable vibrations (low) to noticeable but acceptable (medium) and finally to excessive vibrations that require action (high). The other sets use terms like minor, trivial, or slight, which aren’t the standard three-tier scale used for quick severity assessment, and they mix levels in a way that can blur the line between acceptable and unacceptable vibration. Using low, medium, and high keeps communication precise, so crews know when to monitor, investigate, or take immediate action.