🔍 Key Concepts

• Standard practice for measuring shaft or machinery vibration displacement • Difference between displacement vs velocity vs acceleration units in vibration analysis • Relative size of thousandths, hundredths, and tenths of an inch when evaluating precision measurements

💭 Think About

• If you are measuring small mechanical vibrations on rotating machinery, would you expect the unit to be coarse or very fine? Why? • Which answer choice matches the typical precision needed to detect harmful but still small vibrations in marine machinery? • Think about common dial indicator readings for shaft runout — what order of magnitude is usually used there?

✅ Before You Answer

• Make sure the unit is expressed as inch displacement, not velocity or acceleration units like in/sec or g's • Confirm the description includes peak-to-peak displacement, not just single-amplitude • Compare the order of magnitude of each option with what would be reasonable for rotating machinery tolerances (too big to be useful, or appropriately small?)