Restr:Platinum-Iridium_meter_bar.jpg
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Ment ar rakweled-mañ : 800 × 526 piksel. pizhderioù all : 320 × 210 piksel | 640 × 421 piksel | 1 024 × 673 piksel | 1 280 × 841 piksel | 2 560 × 1 682 piksel | 4 232 × 2 781 piksel.
Restr orin (4 232 × 2 781 piksel, ment ar restr : 2,78 Mio, seurt MIME : image/jpeg)
Tennet eo ar restr-mañ eus Wikimedia Commons ha gallout a ra bezañ implijet evit raktresoù all. Diskouezet eo deskrivadur he fajenn zeskrivañ amañ dindan. |
Diverradur
DeskrivadurPlatinum-Iridium meter bar.jpg |
English: Computer generated image of International Prototype Metre bar, made of 90% platinum - 10% iridium alloy. This was the standard of length for the SI (Metric system) from 1889 until 1960, when the SI system changed to a new definition of length based on the wavelength of light emitted by krypton 86. The length of the metre was defined by the distance between two fine lines ruled on the central rib of the bar near the ends, at the temperature of freezing water. The bar was given an X (Tresca) cross-sectional shape to increase its stiffness-to-weight ratio, improve its thermal accommodation time, and so the graduation lines could be located on the "neutral" axis of the bar where the change in length with flexure is minimum. The prototype was made in 1889, its length made equal to the previous French standard "Metre of the Archives". Twenty-nine identical copies were made at the same time, which were calibrated against the prototype and distributed to nations to serve as national standards. The main problem with defining the unit of length by an artifact such as a bar is that there is no foolproof way of detecting a change in its length due to age or misuse. It can be compared to other copies, but these themselves may have changed in length. This motivated the 1960 change to a definition based on light waves. The bar is now kept in the collection of the BIPM museum. |
Deiziad |
Deiziad dianav Unknown date |
Mammenn |
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Aozer | Unknown authorUnknown author |
Aotre (Adimplij ar restr-mañ) |
Public Domain - work by employee of US Federal Government. Disclaimer on website: "With the exception of material marked as copyrighted, information presented on these pages is considered public information and may be distributed or copied." |
Aotre-implijout
Public domainPublic domainfalsefalse |
This image is in the public domain in the United States because it is a work of the United States Federal Government, specifically an employee of the National Institute of Standards and Technology, under the terms of Title 17, Chapter 1, Section 105 of the US Code.
English ∙ 日本語 ∙ македонски ∙ Nederlands ∙ +/− |
Items portrayed in this file
diskouez a ra
Istor ar restr
Klikañ war un deiziad/eur da welet ar restr evel ma oa da neuze.
Deiziad/Eur | Munud | Mentoù | Implijer | Notenn | |
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red | 14 Her 2013 da 18:11 | 4 232 × 2 781 (2,78 Mio) | Xosema | Higher resolution. | |
1 Mae 2005 da 15:18 | 270 × 175 (21 Kio) | Svdmolen | International Prototype Metre standard bar made of platinum-irridium. This was the standard until 1960, when the new SI system used a krypton-spectrum measurement as the base. In 1983 the current metre was defined by a relationship to the speed of light i |
Implij ar restr
Implijout a ra ar bajenn da heul ar restr-mañ :
Implij hollek ar restr
Ober a ra ar wikioù da-heul gant ar restr-mañ :
- Implij war af.wikipedia.org
- Implij war als.wikipedia.org
- Implij war an.wikipedia.org
- Implij war ar.wikipedia.org
- Implij war arz.wikipedia.org
- Implij war ast.wikipedia.org
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Gwelet muioc'h eus implij hollek ar restr-mañ.
Metaroadennoù
Titouroù ouzhpenn zo er restr-mañ; bet lakaet moarvat gant ar c'hamera niverel pe ar skanner implijet evit he niverelaat. Mard eo bet cheñchet ar skeudenn e-keñver he stad orin marteze ne vo ket kenkoulz munudoù zo e-keñver ar skeudenn kemmet.
Ledander | 4 232 px |
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Hed | 2 781 px |
Niv. a vitoù dre barzhioù |
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Seurt gwaskadur | Hep gwaskañ |
Kenaozadur piksel | RGB |
Tuadur | Boutin |
Niver a standilhonoù | 3 |
Pizhder led ar skeudenn | 600 dpi |
Pizhder hed ar skeudenn | 600 dpi |
Kempenn ar roadennoù | Roadennoù kenstok |
Meziant bet implijet | Adobe Photoshop CS2 Windows |
Deiziad hag eur kemm restr | 27 C'hwe 2008 da 14:58 |
Lec'h al livioù | N'eo ket diouzh ur stalon |
Ledander ar skeudenn | 4 232 px |
Sav ar skeudenn | 2 781 px |
Deiziad hag eur an niverelaat | 27 C'hwe 2008 da 09:58 |
Deiziad ma voe kemmet ar metaroadennoù da ziwezhañ | 27 C'hwe 2008 da 09:58 |
Stumm IIM | 2 |
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