Which instrument is used to diagnose bearing conditions on a rotating machine?

• A. Vibration meter
• B. Tachometer
• C. Stethoscope
• D. Oscilloscope

Answer: (A)

Diagnosing bearing conditions on rotating equipment relies on sensing the vibration that faulty bearings produce as parts move and interact. A vibration meter is designed to measure the level and character of that vibration, and with a proper sensor and analysis (often including frequency analysis), it reveals abnormal patterns and fault frequencies associated with bearing wear, misalignment, or lubrication issues. This quantitative insight lets you detect and diagnose bearing problems more reliably than just listening or measuring speed. A tachometer only measures rotational speed, which doesn’t indicate bearing health. A stethoscope provides qualitative hearing without precise data, and an oscilloscope can show waveforms but isn’t as targeted for bearing diagnosis unless paired with the right transducer and analysis.