An accelerometer is a device for measuring acceleration. An accelerometer inherently measures its own motion, in contrast to a device based on remote sensing.
One application for accelerometers is to measure gravity, wherein an accelerometer is specifically configured for use in gravimetry. Such a device is called a gravimeter.
Accelerometers are used along with gyroscopes in inertial guidance systems, as well as in many other scientific and engineering systems. One of the most common uses for micro electro-mechanical system (MEMS) accelerometers is in airbag deployment systems for modern automobiles. In this case the accelerometers are used to detect the rapid deceleration of the vehicle to determine when a collision has occurred and the severity of the collision.
Accelerometers are perhaps the simplest MEMS device possible sometimes consisting of little more than a suspended cantilever beam or proof mass with some type of deflection sensing and circuitry. MEMS Accelerometers are available in a wide variety of ranges up to thousands of gn's. Single axis, dual axis, and three axis models are available.
The widespread use of accelerometers in the automotive industry has pushed their cost down dramatically.
There is currently research investigating using accelerometers to help estimate the location of devices. The Global Positioning System can only provide information to a device where it can receive signals. When a device is in a tunnel, it can make use of an accelerometer to infer position.
Types of accelerometer:
* Piezo-film
* Surface Micromachined Capacitive (MEMS), Analog Devices, Motorola
* Thermal (submicron CMOS process), MEMSIC
* Bulk Micromachined Capacitive, VTI Technologies Oy
* Bulk Micromachined Piezo Resistive
* PiezoElectric
* Electromechanical Servo (Servo Force Balance ???)
* null-balance
* strain gauge
* resonance
* magnetic induction
* optical
* Surface Acoustic Wave (SAW)