# accelerometer

accelerometer
/ak sel'euh rom"i teuhr/, n.
an instrument for measuring acceleration, as of aircraft or guided missiles.
[1900-05; ACCELER(ATION) + -O- + -METER]

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Instrument that measures acceleration.

Because it is difficult to measure acceleration directly, the device measures the force exerted by restraints placed on a reference mass to hold its position fixed in an accelerating body. The output is usually either a varying electrical voltage or displacement of a moving pointer over a fixed scale. Specially designed accelerometers are used in varied applications: control of industrial vibration test equipment, detection of earthquakes (seismographs), and input to navigational and inertial guidance systems.

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instrument that measures the rate at which the velocity of an object is changing (i.e., its acceleration). Acceleration cannot be measured directly. An accelerometer, therefore, measures the force exerted by restraints that are placed on a reference mass to hold its position fixed in an accelerating body. Acceleration is computed using the relationship between restraint force and acceleration given by Newton's second law: force = mass × acceleration.

The output of an accelerometer is usually in the form of either a varying electrical voltage or a displacement of a moving pointer over a fixed scale. The former type, called a spring-mass accelerometer, incorporates a mass suspended by four precisely designed and matched springs; movement of the mass is restrained by a damper. The accelerometer housing is solidly attached to the moving object.

As the object accelerates, inertia causes the suspended mass to lag behind as its housing moves ahead (accelerates with the object). The displacement of the suspended mass within its housing is proportional to the acceleration of the object. This displacement is converted to an electrical output by a pointer fixed to the mass moving over the surface of a potentiometer attached to the housing. Since the current supplied to the potentiometer remains constant, the movement of the pointer causes the output voltage to vary directly with the acceleration.

Specially designed accelerometers are used in applications as varied as control of industrial vibration test equipment, detection of earthquakes (seismographs), and input to navigational and inertial guidance systems. The design differences are primarily concerned with the method used to convert acceleration to a proportional electrical voltage. These methods include the direct pressure of a mass on a piezoelectric crystal and the electrically sensed displacement of a damped pendulum.

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Universalium. 2010.

### Look at other dictionaries:

• Accelerometer — Ac*cel er*om e*ter, n. [Accelerate + meter.] An apparatus for measuring the velocity imparted by gunpowder. [1913 Webster] …   The Collaborative International Dictionary of English

• accelerometer — ☆ accelerometer [ak sel΄ər äm′ət ər, ak sel΄ə räm′ət ər; əksel΄ər äm′ət ər, əksel΄ə räm′ət ər ] n. [ ACCELER(ATE) + O + METER] a mechanical or electromechanical instrument for measuring acceleration, as of an aircraft, or for detecting vibrations …   English World dictionary

• Accelerometer — An accelerometer is a device for measuring acceleration and gravity induced reaction forces.Single and multi axis models are available to detect magnitude and direction of the acceleration as a vector quantity [http://www.analog.com/en/technical… …   Wikipedia

• Accelerometer — Ein Beschleunigungssensor ist ein Sensor (Fühler), der die Beschleunigung misst, indem die auf eine Testmasse wirkende Trägheitskraft bestimmt wird. Somit kann z. B. bestimmt werden, ob eine Geschwindigkeitszunahme oder abnahme stattfindet. Der… …   Deutsch Wikipedia

• Accelerometer — akcelerometras statusas T sritis automatika atitikmenys: angl. accelerometer vok. Accelerometer, n; Akzelerometer, n; Beschleunigungsmeßgerät, n; Beschleunigungsmesser, m rus. акселерометр, m pranc. accéléromètre, m ryšiai: sinonimas – pagreičio… …   Automatikos terminų žodynas

• accelerometer — akcelerometras statusas T sritis automatika atitikmenys: angl. accelerometer vok. Accelerometer, n; Akzelerometer, n; Beschleunigungsmeßgerät, n; Beschleunigungsmesser, m rus. акселерометр, m pranc. accéléromètre, m ryšiai: sinonimas – pagreičio… …   Automatikos terminų žodynas

• Accelerometer — akcelerometras statusas T sritis Standartizacija ir metrologija apibrėžtis Judančio kūno, pvz., automobilio, orlaivio, erdvėlaivio, raketos ir pan., pagreičio matuoklis. atitikmenys: angl. accelerometer vok. Accelerometer, n; Akzelerometer, n;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• accelerometer — akcelerometras statusas T sritis Standartizacija ir metrologija apibrėžtis Judančio kūno, pvz., automobilio, orlaivio, erdvėlaivio, raketos ir pan., pagreičio matuoklis. atitikmenys: angl. accelerometer vok. Accelerometer, n; Akzelerometer, n;… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• accelerometer — An instrument for measuring acceleration along the normal (vertical), longitudinal, or lateral axis of an aircraft or missile. Accelerometers, which are fitted in aircraft cockpits, are called g meters. Most aircraft accelerometers indicate… …   Aviation dictionary

• accelerometer — noun Etymology: International Scientific Vocabulary acceleration + o + meter Date: circa 1890 an instrument for measuring acceleration or for detecting and measuring vibrations …   New Collegiate Dictionary