Accelerometers are also used to arm the nuclear warheads in a ballistic missile. The warheads are only armed when they reach terminal velocity falling toward the target, so there is no danger of an accidental detonation if something goes wrong at launch, and no terrorist could detonate a stolen warhead without dropping it out of a high-flying aircraft.

A device for measuring acceleration. Sometimes used by high school students during physics field trips to amusement parks. Also used to trigger air bag deployment in cars.

The accelerometer is also the base of any inertial navigation system such as some aircraft autopilots, or ship nav systems. A set of accelerometers continually measures acceleration in all three dimensions; the second integral (thanks baffo!) of these values will give you the distance traveled in each direction from the starting point (well, not that simply, but using that method).

Many accelerometers utilize gyros of some sort, from mechanical gyroscopes to ring laser gyros.

Accelerometers can also be used to measure G-forces.

How it works.

Plate B is in this case suspended between plate A and plate C. While stationary or while not accelerating or decelerating (maintaining a constant speed), plate B is equidistant from the two outer plates. When a car accelerates or an aircraft pulls up sharply plate B will shift closer to one of the other 2 plates. One example of an accelerometer uses electricity flow to measure acceleration, as plate B nears A or C then the electricity flow will gradually increase also.

 _       _       _
| |     | |     | |
| |/////| |/////| |
| |     | |     | |
| |     | |     | |
| |/////| |/////| |
|_|     |_|     |_|
 A       B       C

Source: http://www.vericomcomputers.com/HowItWorks.htm

Ac*cel`er*om"e*ter (#), n. [Accelerate + -meter.]

An apparatus for measuring the velocity imparted by gunpowder.

 

© Webster 1913.