meter for detecting or comparing or measuring small electric currents
A device used to indicate the presence and direction of a small electric current, especially used to detect a null or balanced condition in a bridge circuit.
an instrument or apparatus for measuring the intensity of an electric current, usually by the deflection of a magnetic needle
Origin: [Galvanic + -meter: cf. F. galvanomtre.]
A galvanometer is a type of sensitive ammeter: an instrument for detecting electric current. It is an analog electromechanical actuator that produces a rotary deflection of some type of pointer in response to electric current flowing through its coil in a magnetic field. Galvanometers were the first instruments used to detect and measure electric currents. Sensitive galvanometers were used to detect signals from long submarine cables, and were used to discover the electrical activity of the heart and brain. Some galvanometers used a solid pointer on a scale to show measurements, other very sensitive types used a tiny mirror and a beam of light to provide mechanical amplification of tiny signals. Initially a laboratory instrument relying on the Earth's own magnetic field to provide restoring force for the pointer, galvanometers were developed into compact, rugged, sensitive portable instruments that were essential to the development of electrotechnology. A type of galvanometer that permanently recorded measurements was the chart recorder. The term has expanded to include uses of the same mechanism in recording, positioning, and servomechanism equipment.
The Standard Electrical Dictionary
An instrument for measuring current strength and sometimes for measuring inferentially potential difference, depending on the action of a magnetic field established by the current, such action being exerted on a magnetic needle or its equivalent. A current passing through a conductor establishes circular lines of force. A magnetic needle placed in their field is acted on and tends to place itself parallel with the lines, in accordance with the principles of current induction. (See Induction, Electro-magnetic.) A common compass held near a conductor through which a current is passing tends to place itself at right angles to such conductor. For a maximum effect the conductor or the part nearest the needle should lie in the magnetic meridian. If at right angles thereto its action will only strengthen the directive force of the earth's induction or magnetic field, as the needle naturally points north and south. Such combination is virtually a galvanometer. A typical galvanometer comprises a flat coil of wire placed horizontally within which a magnetic needle is delicately poised, so as to be free to rotate with the least possible friction. The needle may be supported on a sharp point like a compass needle, or may be suspended by a long fine filament. It should be covered by a glass plate and box, or by a glass shade. Finally a graduated disc may be arranged to show the amount of deflection of the needle. In use the apparatus is turned about until the needle, as acted on by the earth's magnetic field, lies parallel to the direction of the coils of wire. On passing a current through the coil the needle is deflected, more or less, according to its strength. By using exceedingly fine wire, long enough to give high resistance, the instrument can be used for very high potentials, or is in condition for use in determining voltage. By using a coil of large wire and low resistance it can be employed in determining amperage. In either case the deflection is produced by the current. The needle is often placed above or below the coil so as only to receive a portion of its effect, enough for all practical purposes in the commoner class of instruments. The galvanometer was invented by Schweigger a short time after Oersted's discovery, q. v.
The numerical value of galvanometer in Chaldean Numerology is: 1
The numerical value of galvanometer in Pythagorean Numerology is: 7
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"galvanometer." Definitions.net. STANDS4 LLC, 2017. Web. 23 Jul 2017. <http://www.definitions.net/definition/galvanometer>.