Here's the triple-axis accelerometer picking up movement as I balance it on my hand.
Accelerometers are used to measure the motion and vibration of a structure that is exposed to dynamic loads. Dynamic loads originate from a variety of sources including:
Human activities – walking, running, dancing or skipping
Working machines – inside a building or in the surrounding area
Construction work – driving piles, demolition, drilling and excavating
Moving loads on bridges
Impact loads – falling debris
Concussion loads – internal and external explosions
Collapse of structural elements
Wind loads and wind gusts
Air blast pressure
Loss of support because of ground failure
Earthquakes and aftershocks
Accelerometers have multiple applications in industry and science. Highly sensitive accelerometers are components of inertial navigation systems for aircraft and missiles. Accelerometers are used to detect and monitor vibration in rotating machinery.
Accelerometers are used in tablets and digital cameras so that images on screens are always displayed upright. Accelerometers are used in drones for flight stabilisation. Coordinated accelerometers can be used to measure differences in proper acceleration, particularly gravity, over their separation in space; i.e., gradient of the gravitational field. This gravitational geometry is useful because absolute gravity is a weak effect and depends on local density of the Earth which is quite variable.
Single- and multi-axis models of accelerometer are available to detect magnitude and direction of the proper acceleration, as a vector quantity, and can be used to sense orientation (because direction of weight changes), coordinate acceleration, vibration, shock, and falling in a resistive medium (a case where the proper acceleration changes, since it starts at zero, then increases).
Micromachined microelectromechanical systems (MEMS) accelerometers are increasingly present in portable electronic devices and video game controllers, to detect the position of the device or provide for game input.