Basic Definitions

Acceleration is the rate of change of velocity. Measurement units for acceleration include m/s², ft/s², and g.

An accelerometer is a sensor, or transducer, which is designed to generate an electrical signal in response to acceleration (or deceleration) that is applied along (parallel with) its sensitive axis.

The applied, or experienced acceleration can fall into one or more of the following categories:

Constant Acceleration - acceleration that does not change during an event. Examples include the acceleration due to earth's gravity or the centrifugal acceleration of a merry-go-round at constant rotational speed.

Transient Acceleration - acceleration that varies over the duration of the event, but is not repetitive. Examples include the deceleration that an automobile undergoes during braking or the acceleration effects experienced by a roller coaster as it negotiates its track. Transient acceleration is the result of discontinuous motion.

Periodic Acceleration - acceleration that continuously varies over the duration of the event, and is quite repetitive. Examples include the vibration of rotating machinery such as motors and bearings or the acceleration experienced by a free-swinging pendulum. Periodic acceleration is the result of continuous motion.