Vibration Theory & Terminology: Amplitude
WARNING: This page does not describe the selected car, but rather 58 other vehicles, including the 2003 Saturn Vue, 2003 Saturn L300, 2003 Saturn Ion 3, 2003 Saturn Ion 2, and 2003 Saturn Ion 1. However, it is still accessible from the selected car via links, so may be relevant.
Amplitude is the maximum value of a periodically varying quantity. See Fig 1 . Used in vibration diagnostics, we are referring it to the magnitude of the disturbance. A severe disturbance would have a high amplitude; a minor disturbance would have a low amplitude.
Amplitude is measured by the amount of actual movement, or the displacement. For example, consider the vibration caused by an out-of-balance wheel at 50 MPH as opposed to 25 MPH. As the speed increases, the amplitude increases.