Definition - What does Amplitude mean?
The amplitude of a vibrating body is the maximum displacement or distance moved by a point on the object from its initial position, and is equal to half the length of the full vibrational movement.
The amplitude of a vibrating specimen in a liquid plays an essential role in the severity of the resulting erosion corrosion due to cavitation.
Corrosionpedia explains Amplitude
Cavitation occurs when a rapidly vibrating or oscillating object in a liquid (e.g., a pump impeller) causes an area of low pressure to form near the object. If the pressure drops below the vapor pressure of the liquid, the liquid boils, causing vapor bubbles to form. These collapsing bubbles can then release shockwaves and high-pressure water jets, which can cause metal parts and components to erode.
As a common example, the amplitude of a pendulum is the maximum distance from its rest position (when the string is vertical) to the greatest height it swings to on either side. Amplitude can also be defined as one-half the distance of the pendulum’s full range of motion from one side to another.