Vibration Test Basic Knowledge - The Terms of Vibration Test

Displacement - The distance that a vibrating mass moves.

Peak displacement, center-to-peak
Peak-to-Peak is the distance between the two farthest points of motion.
Units:  Inches or Millimeters
 
Velocity - The speed at which the vibrating mass moves.

Units: Inches per second or Meters per Second
 
Acceleration - The rate at which the vibrating mass changes speed.
Units: "g" peak for Sine and Shock "Grms" for Random, Sine-on-Random, and Random-on-Ran
 
Frequency - The number of times an oscillation occurs in a period of time.
Units: Hertz (Hz) or Cycles per Second
 
Mass - The amount of matter contained in a body or product
 
Force - The applied energy causing motion or a change in motion
Units: Force Pounds (lbf) or Newtons(N)
 
Power Spectral Density(PSD) - Is a measurement of amplitude and frequency in a Random Vibration spectrum.
Units: Amplitude: (y axis) g2/Hz or (m/S2)2/Hz

Frequency - (x axis) Hertz (Hz)