Fasciculus:Platinum-Iridium_meter_bar.jpg
From Wikipedia, the free encyclopedia
Mensura huius perspectionis: 800 × 526 elementa imaginalia. Aliae mensurae: 320 × 210 elementa imaginalia | 640 × 421 elementa imaginalia | 1 024 × 673 elementa imaginalia | 1 280 × 841 elementa imaginalia | 2 560 × 1 682 elementa imaginalia | 4 232 × 2 781 elementa imaginalia.
Sua resolutio (4 232 × 2 781 elementa imaginalia, magnitudo fasciculi: 2.78 megaocteti, typus MIME: image/jpeg)
Hic fasciculus apud Vicimedia Communia iacet; in aliis inceptis adhiberi potest. Contenta paginae descriptionis fasciculi subter monstrantur.
Summarium
DescriptioPlatinum-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. |
Datum |
Dies ignota Unknown date |
Fons |
|
Auctor | Unknown authorUnknown author |
Permissio (Reusing this file) |
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." |
Potestas usoris
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
depicts Anglica
Historia fasciculi
Presso die vel tempore fasciculum videbis, sicut tunc temporis apparuit.
Dies/Tempus | Minutio | Dimensiones | Usor | Sententia | |
---|---|---|---|---|---|
recentissima | 18:11, 14 Octobris 2013 | 4 232 × 2 781 (2.78 megaocteti) | Xosema | Higher resolution. | |
15:18, 1 Maii 2005 | 270 × 175 (21 chiliocteti) | 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 |
Nexus ad fasciculum
Ad hunc fasciculum nectit:
Usus fasciculi per inceptus Vicimediorum
Quae incepta Vici fasciculo utuntur:
- Usus in af.wikipedia.org
- Usus in als.wikipedia.org
- Usus in an.wikipedia.org
- Usus in ar.wikipedia.org
- Usus in arz.wikipedia.org
- Usus in ast.wikipedia.org
- Usus in azb.wikipedia.org
- Usus in az.wikipedia.org
- Usus in ba.wikipedia.org
- Usus in be-tarask.wikipedia.org
- Usus in be.wikipedia.org
- Usus in bg.wikipedia.org
- Usus in br.wikipedia.org
- Usus in bs.wikipedia.org
- Usus in ca.wikipedia.org
- Usus in ce.wikipedia.org
- Usus in cs.wikipedia.org
- Usus in cu.wikipedia.org
- Usus in cv.wikipedia.org
- Usus in cy.wikipedia.org
- Usus in da.wikipedia.org
- Usus in de.wikipedia.org
- Usus in el.wikipedia.org
- Usus in en.wikipedia.org
View more global usage of this file.
Metadata
Hic fasciculus alias res continet, saepius a machina originatore additas, et (si fasciculus postea recensus sit) fortasse corrigendas.
Amplitudo | 4 232 px |
---|---|
Altitudo | 2 781 px |
Biti per componentem |
|
Schema compressionis | Incompressus |
Compositio elementorum imaginalium | RGB |
Orientatio | Normalis |
Numerus componentum | 3 |
Resolutio horizontalis | 600 dpi |
Resolutio verticalis | 600 dpi |
Data arrangement | formatio dilatata |
Software used | Adobe Photoshop CS2 Windows |
Dies et hora mutationis | 14:58, 27 Februarii 2008 |
Spatium colorimetricum | Uncalibrated |
Amplitudo imaginis | 4 232 px |
Altitudo imaginis | 2 781 px |
Dies digitizationis | 09:58, 27 Februarii 2008 |
Date metadata was last modified | 09:58, 27 Februarii 2008 |
IIM version | 2 |