# torsion balance

torsion balance
an instrument for measuring small forces, as electric attraction or repulsion, by determining the amount of torsion or twisting they cause in a slender wire or filament.
[1820-30]

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Device used to measure the gravitational acceleration at the Earth's surface.

It consists essentially of two small masses at different elevations that are supported at opposite ends of a beam. The latter is suspended from a wire that twists because the masses are affected differently by the force of gravity. When the wire is twisted, an optical system indicates the angle of deflection, and the torque, or twisting force, can be calculated. The torque is correlated with the gravitational force at the point of observation. Torsion balance may also refer to a device used in weighing, a type of equal-arm balance.

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▪ measurement instrument
device used to measure the gravitational acceleration at the Earth's surface. Other such devices, using different methods to obtain the same result, are pendulums and gravimeters. The torsion balance consists essentially of two small masses at different elevations that are supported at opposite ends of a beam. The latter is suspended from a wire that undergoes torsion because the masses are affected differently by the force of gravity. When the wire is twisted, an optical system indicates the angular deflection (θ), and the torque (T), or twisting force, involved can be calculated from the simple expression T = kθ, in which k is a constant that depends on the properties of the instrument. The amount of torque, in turn, is correlated with the gravitational force at the point of observation. The torsion balance was devised by Lóránt von Eötvös, a Hungarian physicist, in 1902; many scientists have contributed modifications to the basic instrument.

The term torsion balance also refers to a device used in weighing, an equal arm balance that uses horizontal steel bands instead of pivots and bearings.

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Universalium. 2010.

### Look at other dictionaries:

• Torsion balance — Torsion Tor sion, n. [F., fr. LL. torsio, fr. L. torquere, tortum, to twist. See {Torture}.] 1. The act of turning or twisting, or the state of being twisted; the twisting or wrenching of a body by the exertion of a lateral force tending to turn… …   The Collaborative International Dictionary of English

• torsion balance — n. an instrument for measuring small forces, such as those caused by gravitation, electric charges, or magnetism, by recording the amount of torsion they produce in a fine wire …   English World dictionary

• torsion balance — sukamosios svarstyklės statusas T sritis Standartizacija ir metrologija apibrėžtis Mikrosvarstyklės, kurių veikimas pagrįstas metalo arba kvarco spiralės ar siūlo priešinimusi sukimui arba lenkimui. atitikmenys: angl. Coulomb’s balance; torsion… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• torsion balance — sukamosios svarstyklės statusas T sritis Standartizacija ir metrologija apibrėžtis Svarstyklės silpnoms elektrostatinėms, magnetinėms, gravitacinėms jėgoms matuoti. atitikmenys: angl. Coulomb’s balance; torsion balance vok. Coulomb Torsionswaage …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• torsion balance — Kevendišo svarstyklės statusas T sritis Standartizacija ir metrologija apibrėžtis Sukamosios svarstyklės labai silpnoms jėgoms matuoti. atitikmenys: angl. Cavendish balance; torsion balance vok. Cavendishsche Drehwaage, f rus. весы Кавендиша… …   Penkiakalbis aiškinamasis metrologijos terminų žodynas

• torsion balance — Kevendišo svarstyklės statusas T sritis fizika atitikmenys: angl. Cavendish balance; torsion balance vok. Cavendishsche Drehwaage, f rus. весы Кавендиша pranc. balance de torsion de Cavendish, f …   Fizikos terminų žodynas

• torsion balance — sukamosios svarstyklės statusas T sritis fizika atitikmenys: angl. torsion balance vok. Drehwaage, f; Torsionswaage, f; Verdrehungswaage, f rus. крутильные весы pranc. balance de torsion, f …   Fizikos terminų žodynas

• torsion balance — sukamosios svarstyklės statusas T sritis chemija apibrėžtis Mikrosvarstyklės, kuriose panaudojamas metalo (kvarco) spiralės ar siūlo priešinimasis sukimui arba lenkimui. atitikmenys: angl. torsion balance rus. крутильные весы; торзионные весы …   Chemijos terminų aiškinamasis žodynas

• torsion balance — 1. a balance used in the laboratory, having a scale beam supported by metallic ribbons that act by torsion. 2. an electrometer that acts by the twisting of a single fiber of the web of a silkworm …   Medical dictionary

• torsion balance — /ˈtɔʃən bæləns/ (say tawshuhn baluhns) noun an instrument for measuring small forces (as electrical attraction or repulsion) by determining the amount of torsion or twisting they cause in a slender wire or filament …