Vibration terminology

Principale of vibration

Vibration means the state of an object moving repetitively back/forward, right/ left or up/down and is generally expressed by Frequency, Displacement, Velocity, and Acceleration. These 4 elements are generally denoted as F, D,V,A. This is illustrated simply as a spring and mass. When the mass is pulled down from the start position and released, the mass moves just like the vibration waveform shown in the graph on the right.

  • Frequency(F)
    Frequency means the number of times that vibrating object generates a repetitive motion in 1 second.
  • Displacement(D)
    Displacement means the amplitude (distance) between the peaks of vibration.
    Unit:μm, mm
  • Velocity(V)
    Velocity means the changing rate of displacement (D) to time
    Unit:mm/s, cm/s
  • Acceleration(A)
    Acceleration means the changing rate of velocity(V) to time
    Unit:m/s2, g
  • H function
    Effective function to detect abnormal bearing noise. 2kHz~15kHz filtering to acceleration waveform can remove noise for waveform analysis.