tuning fork

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tuning fork,

steel instrument in the shape of a U with a short handle. When struck it produces an almost pure tone, retaining its pitch over a long period of time; thus it is a valuable aid in tuning musical instruments. It was invented in 1711 by John Shore, who jokingly called it a pitchfork.

Tuning fork

A steel instrument consisting of two prongs and a handle which, when struck, emits a tone of fixed pitch. Because of their simple mechanical structure, purity of tone, and constant frequency, tuning forks are widely used as standards of frequency in musical acoustics. In its electrically driven form, a tuning fork serves to control electric circuits by producing frequency standards of high accuracy and stability. A tuning fork is essentially a transverse vibrator (see illustration). See Vibration

A tuning fork vibrating at its fundamental frequencyenlarge picture
A tuning fork vibrating at its fundamental frequency

Tuning Fork

 

a source of sound, consisting of a metal rod that is bent and fixed in the center. The ends of the rod can vibrate freely. During the tuning of musical instruments, the tuning fork serves as the standard pitch of a tone; it is also used to give the pitch in singing. Forks that produce the tone A’ (A of the first octave) are usually used. Singers and choral conductors also use forks producing the tone C”. There are chromatic tuning forks, with prongs that have movable little weights. Depending on the position of these weights, the prongs vibrate at different frequencies.

The tuning fork was invented by the English musician J. Shore in 1711. At that time the standard frequency of vibrations for the tone A’ was 419.9 hertz (Hz). In the late 18th century the composer and conductor G. Sarti, who was working in St. Petersburg, introduced the “St. Petersburg tuning fork,” with an A’ = 436 Hz. In 1858 the Paris Academy of Sciences proposed a standard pitch tuning fork with A’ = 435 Hz. In 1885 at an international conference in Vienna this frequency was adopted as the international standard pitch for the tone A’; the frequency was called the standard musical pitch. Since Jan. 1, 1936, an all-Union standard pitch of A’ = 440 Hz has been in effect in the USSR.

REFERENCE

MuzykaVnaia akustika. Edited by N. A. Garbuzov. Moscow-Leningrad, 1940.

tuning fork

[′tün·iŋ ‚fȯrk]
(engineering)
A U-shaped bar for hard steel, fused quartz, or other elastic material that vibrates at a definite natural frequency when struck or when set in motion by electromagnetic means; used as a frequency standard.

tuning fork

a two-pronged metal fork that when struck produces a pure note of constant specified pitch. It is used to tune musical instruments and in acoustics
References in periodicals archive ?
As a result of the acquisition of Hertz, Kyocera Kinseki will be able to integrate its own manufacturing technology with Hertz's basic technology and processing technology for tuning-fork crystals, and will be able to increase its manufacturing volume for crystal devices.
In addition, Kyocera Kinseki will be able to expand its business as a total crystal device manufacturer by adding tuning-fork crystal units, not currently manufactured by it, to its products lineup and by enhancing its products for the wireless communication market.
Drawbacks include higher cost--typically $400 to $800--and the tuning-fork type tends to be sensitive to material build-up between the tines.
Siemens has introduced a new tuning-fork level switch, the Pointek VLS 200, primarily for fluffy and other low-bulk-density materials down to 1.
The patient exhibited no response to tuning-fork testing or to distraction testing with a bell rung at ear level.
Table 94: Asia-Pacific Historic Review for Level Sensors by Technology - Magnetostrictive, Tuning-Fork, Hydrostatic, Capacitance, Conductivity, Ultrasonic, Radar-Microwave and Other Markets Independently Analyzed with Annual Sales Figures in US$ Thousand for Years 2006 through 2012 (includes corresponding Graph/Chart) III-58 Table 95: Asia-Pacific 15-Year Perspective for Level Sensors by Technology - Percentage Breakdown of Dollar Sales for Magnetostrictive, Tuning-Fork, Hydrostatic, Capacitance, Conductivity, Ultrasonic, Radar-Microwave and Other Markets for Years 2006, 2014 & 2020 (includes corresponding Graph/Chart) III-59
Table 14: World Recent Past, Current & Future Analysis for Tuning-Fork Level Sensors by Geographic Region - US, Canada, Europe, Asia-Pacific (including Japan), and Rest of World Markets Independently Analyzed with Annual Sales in US$ Million for Years 2006 through 2015 (includes corresponding Graph/Chart) II-56
Table 15: World 10-Year Perspective for Tuning-Fork Level Sensors by Geographic Region - Percentage Breakdown of Value Sales for US, Canada, Europe, Asia-Pacific (including Japan), and Rest of World Markets for Years 2006, 2009 & 2015 (includes corresponding Graph/Chart) II-57
Table 28: US Recent Past, Current & Future Analysis for Level Sensors by Technology - Magnetostrictive, Tuning-Fork, Hydrostatic, Capacitance, Conductivity, Ultrasonic, Radar-Microwave and Other Markets Independently Analyzed with Annual Sales Figures in US$ Million for Years 2006 through 2015 (includes corresponding Graph/Chart) III-15
Table 29: US 10-Year Perspective for Level Sensors by Technology - Percentage Breakdown of Dollar Sales for Magnetostrictive, Tuning-Fork, Hydrostatic, Capacitance, Conductivity, Ultrasonic, Radar-Microwave and Other Markets for Years 2006, 2009 & 2015 (includes corresponding Graph/Chart) III-16
Each child also underwent a tuning-fork test, examination under microscopy, repeat tympanometry, stapedial reflex test, and pure-tone audiometry.