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1 clock-spring steel
clock-spring steel Uhrfederstahl mEnglish-German dictionary of Electrical Engineering and Electronics > clock-spring steel
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2 Harrison, John
[br]b. 24 March 1693 Foulby, Yorkshire, Englandd. 24 March 1776 London, England[br]English horologist who constructed the first timekeeper of sufficient accuracy to determine longitude at sea and invented the gridiron pendulum for temperature compensation.[br]John Harrison was the son of a carpenter and was brought up to that trade. He was largely self-taught and learned mechanics from a copy of Nicholas Saunderson's lectures that had been lent to him. With the assistance of his younger brother, James, he built a series of unconventional clocks, mainly of wood. He was always concerned to reduce friction, without using oil, and this influenced the design of his "grasshopper" escapement. He also invented the "gridiron" compensation pendulum, which depended on the differential expansion of brass and steel. The excellent performance of his regulator clocks, which incorporated these devices, convinced him that they could also be used in a sea dock to compete for the longitude prize. In 1714 the Government had offered a prize of £20,000 for a method of determining longitude at sea to within half a degree after a voyage to the West Indies. In theory the longitude could be found by carrying an accurate timepiece that would indicate the time at a known longitude, but the requirements of the Act were very exacting. The timepiece would have to have a cumulative error of no more than two minutes after a voyage lasting six weeks.In 1730 Harrison went to London with his proposal for a sea clock, supported by examples of his grasshopper escapement and his gridiron pendulum. His proposal received sufficient encouragement and financial support, from George Graham and others, to enable him to return to Barrow and construct his first sea clock, which he completed five years later. This was a large and complicated machine that was made out of brass but retained the wooden wheelwork and the grasshopper escapement of the regulator clocks. The two balances were interlinked to counteract the rolling of the vessel and were controlled by helical springs operating in tension. It was the first timepiece with a balance to have temperature compensation. The effect of temperature change on the timekeeping of a balance is more pronounced than it is for a pendulum, as two effects are involved: the change in the size of the balance; and the change in the elasticity of the balance spring. Harrison compensated for both effects by using a gridiron arrangement to alter the tension in the springs. This timekeeper performed creditably when it was tested on a voyage to Lisbon, and the Board of Longitude agreed to finance improved models. Harrison's second timekeeper dispensed with the use of wood and had the added refinement of a remontoire, but even before it was tested he had embarked on a third machine. The balance of this machine was controlled by a spiral spring whose effective length was altered by a bimetallic strip to compensate for changes in temperature. In 1753 Harrison commissioned a London watchmaker, John Jefferys, to make a watch for his own personal use, with a similar form of temperature compensation and a modified verge escapement that was intended to compensate for the lack of isochronism of the balance spring. The time-keeping of this watch was surprisingly good and Harrison proceeded to build a larger and more sophisticated version, with a remontoire. This timekeeper was completed in 1759 and its performance was so remarkable that Harrison decided to enter it for the longitude prize in place of his third machine. It was tested on two voyages to the West Indies and on both occasions it met the requirements of the Act, but the Board of Longitude withheld half the prize money until they had proof that the timekeeper could be duplicated. Copies were made by Harrison and by Larcum Kendall, but the Board still continued to prevaricate and Harrison received the full amount of the prize in 1773 only after George III had intervened on his behalf.Although Harrison had shown that it was possible to construct a timepiece of sufficient accuracy to determine longitude at sea, his solution was too complex and costly to be produced in quantity. It had, for example, taken Larcum Kendall two years to produce his copy of Harrison's fourth timekeeper, but Harrison had overcome the psychological barrier and opened the door for others to produce chronometers in quantity at an affordable price. This was achieved before the end of the century by Arnold and Earnshaw, but they used an entirely different design that owed more to Le Roy than it did to Harrison and which only retained Harrison's maintaining power.[br]Principal Honours and DistinctionsRoyal Society Copley Medal 1749.Bibliography1767, The Principles of Mr Harrison's Time-keeper, with Plates of the Same, London. 1767, Remarks on a Pamphlet Lately Published by the Rev. Mr Maskelyne Under theAuthority of the Board of Longitude, London.1775, A Description Concerning Such Mechanisms as Will Afford a Nice or True Mensuration of Time, London.Further ReadingR.T.Gould, 1923, The Marine Chronometer: Its History and Development, London; reprinted 1960, Holland Press.—1978, John Harrison and His Timekeepers, 4th edn, London: National Maritime Museum.H.Quill, 1966, John Harrison, the Man who Found Longitude, London. A.G.Randall, 1989, "The technology of John Harrison's portable timekeepers", Antiquarian Horology 18:145–60, 261–77.J.Betts, 1993, John Harrison London (a good short account of Harrison's work). S.Smiles, 1905, Men of Invention and Industry; London: John Murray, Chapter III. Dictionary of National Biography, Vol. IX, pp. 35–6.DV -
3 Arnold, John
SUBJECT AREA: Horology[br]b. 1735/6 Bodmin (?), Cornwall, Englandd. 25 August 1799 Eltham, London, England[br]English clock, watch, and chronometer maker who invented the isochronous helical balance spring and an improved form of detached detent escapement.[br]John Arnold was apprenticed to his father, a watchmaker, and then worked as an itinerant journeyman in the Low Countries and, later, in England. He settled in London in 1762 and rapidly established his reputation at Court by presenting George III with a miniature repeating watch mounted in a ring. He later abandoned the security of the Court for a more precarious living developing his chronometers, with some financial assistance from the Board of Longitude. Symbolically, in 1771 he moved from the vicinity of the Court at St James's to John Adam Street, which was close to the premises of the Royal Society for the Encouragement of Arts, Manufactures \& Commerce.By the time Arnold became interested in chronometry, Harrison had already demonstrated that longitude could be determined by means of a timekeeper, and the need was for a simpler instrument that could be sold at an affordable price for universal use at sea. Le Roy had shown that it was possible to dispense with a remontoire by using a detached escapement with an isochronous balance; Arnold was obviously thinking along the same lines, although he may not have been aware of Le Roy's work. By 1772 Arnold had developed his detached escapement, a pivoted detent which was quite different from that used on the European continent, and three years later he took out a patent for a compensation balance and a helical balance spring (Arnold used the spring in torsion and not in tension as Harrison had done). His compensation balance was similar in principle to that described by Le Roy and used riveted bimetallic strips to alter the radius of gyration of the balance by moving small weights radially. Although the helical balance spring was not completely isochronous it was a great improvement on the spiral spring, and in a later patent (1782) he showed how it could be made more truly isochronous by shaping the ends. In this form it was used universally in marine chronometers.Although Arnold's chronometers performed well, their long-term stability was less satisfactory because of the deterioration of the oil on the pivot of the detent. In his patent of 1782 he eliminated this defect by replacing the pivot with a spring, producing the spring detent escapement. This was also done independendy at about the same time by Berthoud and Earnshaw, although Earnshaw claimed vehemently that Arnold had plagiarized his work. Ironically it was Earnshaw's design that was finally adopted, although he had merely replaced Arnold's pivoted detent with a spring, while Arnold had completely redesigned the escapement. Earnshaw also improved the compensation balance by fusing the steel to the brass to form the bimetallic element, and it was in this form that it began to be used universally for chronometers and high-grade watches.As a result of the efforts of Arnold and Earnshaw, the marine chronometer emerged in what was essentially its final form by the end of the eighteenth century. The standardization of the design in England enabled it to be produced economically; whereas Larcum Kendall was paid £500 to copy Harrison's fourth timekeeper, Arnold was able to sell his chronometers for less than one-fifth of that amount. This combination of price and quality led to Britain's domination of the chronometer market during the nineteenth century.[br]Bibliography30 December 1775, "Timekeepers", British patent no. 1,113.2 May 1782, "A new escapement, and also a balance to compensate the effects arising from heat and cold in pocket chronometers, and for incurving the ends of the helical spring…", British patent no. 1,382.Further ReadingR.T.Gould, 1923, The Marine Chronometer: Its History and Development, London; reprinted 1960, Holland Press (provides an overview).V.Mercer, 1972, John Arnold \& Son Chronometer Makers 1726–1843, London.See also: Phillips, EdouardDV -
4 scale
5) шкала7) масштаб || определять масштаб, масштабировать; изменять масштаб; сводить к определённому масштабу8) мн. ч. весы9) чашка весов10) взвешивать11) электрон. степень интеграции12) вчт. система счисления13) пищ. чешуя; чешуйка; шелуха || удалять чешую; отделяться чешуйками•at scales — в масштабе;to scale down — 1. представлять что-л. в уменьшенном масштабе 2. редуцировать, уменьшать ( изображение) 3. (пропорционально) уменьшать размеры ( элементов ИС) 4. делить на константу;to scale off — 1. выкрашиваться, крошиться (о камне, горной породе) 2. отслаивать(ся); шелушиться 3. удалять окалину 4. отбивать накипь 5. снимать [измерять\] что-л. в масштабе;to draw to scale — чертить [вычерчивать\] в масштабе;to generate a time scale — строить [создавать\] шкалу времени;to maintain a time scale — поддерживать [хранить\] шкалу времени;to mark off a scale in logarithmic units — градуировать шкалу в логарифмических единицах;to place a scale on a dial — градуировать шкалу, наносить отметки шкалы на циферблат;to realize a time scale on a dial — воспроизводить шкалу времени на циферблате часов;to retain a scale — поддерживать [хранить\] шкалу (напр. времени);to scale up — 1. представлять что-л. в увеличенном масштабе 2. увеличивать ( изображение) 3. умножать на константу;scale with central zero — шкала с нулевой отметкой посередине, двусторонняя шкала;-
absolute-temperature scale
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aligning scale
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alkali-promoted steel mill scale
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annual time scale
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antiknock rating reference fuel scale
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antiparallax mirror scale
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API hydrometer scale
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API scale
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arbitrary scale
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arc scale
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atomic scale
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atomic time scale
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atomic weight scale
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automatic weighing scales
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automatic scales
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bagging scale
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batching scales
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beam scale
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Beaufort scale
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belt conveyor scales
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bench-type scales
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binary scale
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boiler scale
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brightness scale
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calibrated divided scale
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calibration scale
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car scales
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CCT-64 scale
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Celsius scale
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centered scale
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centigrade scale
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charging scales
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chromatic scale
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chroma scale
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circular scale
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clock time scale
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colorimetric scale
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color scale
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complete number scale
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constant-interval scale
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constant-pressure gas thermometry scale
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constant-volume gas thermometry scale
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constant-volume hydrogen scale
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continuous tone density scale
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convective scale
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conventional scale
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conveyor scales
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coordinate scale
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crane scales
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Curie-temperature scale
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curved scale
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CVGT scale
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decimal scale
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depth scale
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derived scale
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dial scale
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direct-measurement scale
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direct scale
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direct-reading scale
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displacement scale
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distance scale
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divided scale
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dot gain scale
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drawn-in scale
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electronic railcar scales
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Engler scale
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equidistant scale
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expanded scale
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exposure scale
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extended scale
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Fahrenheit scale
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finely subdivided scale
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fire scale
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fish scale
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flat-disk scale
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floodlight scale
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floor scales
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focusing scale
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Forel-Ula's color scale
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Forel scale
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forklift truck scales
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frosted scale
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fuel measurement scale
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full scale
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furnace scale
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Giaque's temperature scale
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gray scale
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hardness scale
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heavy scale
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helium temperature scale
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high-temperature scale
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hopper scales
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hue scale
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hump scales
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hydrogen scale
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hydrogen temperature scale
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ideal-gas scale
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illuminated scale
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image scale
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indicating scale
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indicator scale
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industrial scales
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instrument scale
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integration scale
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intensity scale
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International Practical Temperature scale
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international scale
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Kelvin temperature scale
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light-capacity scales
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line scale
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linear scale
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line-standard scale
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logarithmic scale
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loudness scale
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low-temperature scale
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magnetic scale
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magnetic temperature scale
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magnetic-acoustic temperature scale
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magnitude scale
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margin scale
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mean-time scale
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measuring device scale
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mechanical scales
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Mercalli scale
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meter scale
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mill-roll scale
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mired scale
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mirror scale
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MM scale
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Modified Mercalli scale
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Mohs scale
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motor-truck scales
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natural scale
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Nernst hydrogen scale
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nominal scale
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nonglare scale
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nonlinear scale
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normal hydrogen scale
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normalizing scale
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number scale
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numbered scale
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octane scale
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one-meter scale
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optical scale
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ordinal scale
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overhead track scales
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overlaid scale
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packing house scales
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paper scale
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paraffin scale
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paramagnetic-salt temperature scale
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paramagnetic temperature scale
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pendulum scales
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photometric scale
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physical scale
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pipe scale
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pitless scales
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platform scales
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platinum resistance thermometer scale
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practical salinity scale
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practical scale
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precision scale
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primary scale
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primary thermometry scale
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projection scale
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provisional scale
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pyrheliographic scale
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radiation scale of temperature
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radiometric scale
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Rankine scale
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ratio scale
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reading scale
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Reaumur scale
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receiver tuning scale
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recording scales
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reduced scale
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reduction scale
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Redwood scale
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reference scale
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regular scale
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relative scale
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reproducible scale
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reproduction scale
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resistance thermometer scale
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Richter scale
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rider bar scale
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rider scale
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Rinman scale
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Rockwell hardness scale
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roll scale
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rolled-in scale
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Rossi-Forel scale
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salt-pan scale
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Saybolt scale
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scale of magnification
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scale of physical quantity
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scale of turbulence
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seasonal time scale
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secondary scale
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segmental scale
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sensitivity scale
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set-point scale
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Shore hardness scale
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sieve scale
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snow scale
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soft dot scale
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solid hydrocarbon scale
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space-time scale
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splash scale
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spring scales
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standard scale
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state of sea scale
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static scales
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straight scale
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subgrid scale
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subsynoptic scale
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synoptic scale
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table-type scales
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temper scale
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temperature scale
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thermodynamic pressure scale
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thermodynamic temperature scale
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time scale
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tone scale
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tonnage scale
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total life scale
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track scales
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transparent aligning scale
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uniform scale
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unit-weight scales
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universal-time scale
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vernier scale
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Vickers hardness scale
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water scale
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white scale
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yarn scales -
5 Guillaume, Charles-Edouard
[br]b. 15 February 1861 Fleurier, Switzerlandd. 13 June 1938 Sèvres, France[br]Swiss physicist who developed two alloys, "invar" and "elinvar", used for the temperature compensation of clocks and watches.[br]Guillaume came from a family of clock-and watchmakers. He was educated at the Gymnasium in Neuchâtel and at Zurich Polytechnic, from which he received his doctorate in 1883 for a thesis on electrolytic capacitors. In the same year he joined the International Bureau of Weights and Measures at Sèvres in France, where he was to spend the rest of his working life. He retired as Director in 1936. At the bureau he was involved in distributing the national standards of the metre to countries subscribing to the General Conference on Weights and Measures that had been held in 1889. This made him aware of the crucial effect of thermal expansion on the lengths of the standards and he was prompted to look for alternative materials that would be less costly than the platinum alloys which had been used. While studying nickel steels he made the surprising discovery that the thermal expansion of certain alloy compositions was less than that of the constituent metals. This led to the development of a steel containing about 36 per cent nickel that had a very low thermal coefficient of expansion. This alloy was subsequently named "invar", an abbreviation of invariable. It was well known that changes in temperature affected the timekeeping of clocks by altering the length of the pendulum, and various attempts had been made to overcome this defect, most notably the mercury-compensated pendulum of Graham and the gridiron pendulum of Harrison. However, an invar pendulum offered a simpler and more effective method of temperature compensation and was used almost exclusively for pendulum clocks of the highest precision.Changes in temperature can also affect the timekeeping of watches and chronometers, but this is due mainly to changes in the elasticity or stiffness of the balance spring rather than to changes in the size of the balance itself. To compensate for this effect Guillaume developed another more complex nickel alloy, "elinvar" (elasticity invariable), whose elasticity remained almost constant with changes in temperature. This had two practical consequences: the construction of watches could be simplified (by using monometallic balances) and more accurate chronometers could be made.[br]Principal Honours and DistinctionsNobel Prize for Physics 1920. Corresponding member of the Académie des Sciences. Grand Officier de la Légion d'honneur 1937. Physical Society Duddell Medal 1928. British Horological Institute Gold Medal 1930.Bibliography1897, "Sur la dilation des aciers au nickel", Comptes rendus hebdomadaires des séances de l'Académie des sciences 124:176.1903, "Variations du module d"élasticité des aciers au nickel', Comptes rendushebdomadaires des séances de l'Académie des sciences 136:498."Les aciers au nickel et leurs applications à l'horlogerie", in J.Grossmann, Horlogerie théorique, Paris, Vol. II, pp. 361–414 (describes the application of invar and elinvar to horology).Sir Richard Glazebrook (ed.), 1923 "Invar and Elinvar", Dictionary of Applied Physics, 5 vols, London, Vol. V, pp. 320–7 (a succinct account in English).Further ReadingR.M.Hawthorne, 1989, Nobel Prize Winners, Physics, 1901–1937, ed. F.N.Magill, Pasadena, Salem Press, pp. 244–51.See also: Le Roy, PierreDVBiographical history of technology > Guillaume, Charles-Edouard
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