🔍 Key Concepts

• Basic vibration measurement terms: displacement, velocity, and another key characteristic • Relationship between vibration and periodic motion (how often the motion repeats) • Difference between electrical quantities (kW, amps) and mechanical vibration quantities

💭 Think About

• Ask yourself: When looking at a vibration signal over time, besides how far it moves (displacement) or how fast it moves (velocity), what characteristic of the motion strongly affects how harmful the vibration is? • Which of the choices is directly related to how many times per second the motion repeats, rather than to electrical power or current? • In machinery diagnostics, what additional vibration parameter must be known to correctly interpret velocity or displacement readings from sensors?

✅ Before You Answer

• Eliminate choices that are clearly electrical rather than mechanical vibration parameters • Decide which option is tied to how often the vibration cycles occur, not just how big the motion is • Confirm that the factor you choose is commonly plotted on the horizontal axis of a vibration spectrum for rotating machinery