Vibration

The back and forth movement or oscillation of machines and their components. Most industrial devices are engineered to operate smoothly and avoid vibration, not produce it. Vibration in industrial equipment can be both a sign and a source of trouble, possibly indicating mechanical problems or internal deterioration. If not corrected, it can cause additional damage. In critical process machinery, it is ideal for a machine to run with vibration levels close to zero.

The most common types of vibration measurements are displacement, velocity, and acceleration. Vibration waveforms have the following characteristics:

• Amplitude — Maximum value of vibration (how much)
• Frequency — Number of cycles or oscillations per unit time (how often, i.e. cycles per minute; cycles per second)
• Phase — Relationship between when a vibration waveform event occurs relative to a reference or timing signal of the same frequency (when is the peak occurring).

See also Forced Vibration; Free Vibration; Harmonic Vibration; Radial Vibration; Torsional Vibration; Vane Passing Vibration.