This is a file from the Wikimedia Commons

File:Watt balance, large view.jpg

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Watt_balance,_large_view.jpg(550 × 474 pixels, file size: 287 KB, MIME type: image/jpeg)

Summary

Description
English: The Watt balance at the US National Institute of Standards and Technology (NIST). This is an experimental, extremely accurate mass measuring instrument. The vacuum chamber dome, above the apparatus, descends during use so it operates in vacuum. The Watt balance measures mass by comparing it to atomic units, Planck's constant and the speed of light. It is being developed to provide a more accurate standard of mass than the current one. Currently the primary standard defining all the world's mass and weight units is the International Prototype Kilogram (IPK), a cylinder of platinum-iridium alloy kept in a vault at Sevres, France. It is the only unit defined by a physical artifact, so it is vulnerable to damage and deterioration over the years, and in fact has been found to vary in mass. When it is perfected, the Watt balance will be used to "weigh" the IPK, defining the kilogram by atomic units so a physical prototype will not be needed, creating an "electronically" defined kilogram.
Date (original upload date)
Source Transferred from en.wikipedia to Commons by Mormegil using CommonsHelper.
Author Photo by Richard Steiner (The original uploader was Greg L at English Wikipedia.)
Permission
(Reusing this file)
OTRS Wikimedia

This work is free and may be used by anyone for any purpose. If you wish to use this content, you do not need to request permission as long as you follow any licensing requirements mentioned on this page.

Wikimedia Foundation has received an e-mail confirming that the copyright holder has approved publication under the terms mentioned on this page. This correspondence has been reviewed by an OTRS member and stored in our permission archive. The correspondence is available to trusted volunteers as ticket #2007101710016867.

If you have questions about the archived correspondence, please use the OTRS noticeboard.

Ticket link: https://ticket.wikimedia.org/otrs/index.pl?Action=AgentTicketZoom&TicketNumber=2007101710016867

Licensing

GNU head Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.
This licensing tag was added to this file as part of the GFDL licensing update.

Original upload log

The original description page was here. All following user names refer to en.wikipedia.
  • 2007-10-18 00:38 Greg L 550×474×8 (293997 bytes)
  • 2007-10-17 23:51 Greg L 550×484×8 (236377 bytes)
  • 2007-10-17 23:35 Greg L 500×412×8 (199416 bytes) The NIST’s Watt balance. The vacuum chamber dome can be seen above the apparatus. Photo by Richard Steiner

Captions

Add a one-line explanation of what this file represents

Items portrayed in this file

depicts

17 October 2007

File history

Click on a date/time to view the file as it appeared at that time.

Date/TimeThumbnailDimensionsUserComment
current12:54, 23 July 2008Thumbnail for version as of 12:54, 23 July 2008550 × 474 (287 KB)File Upload Bot (Magnus Manske) {{BotMoveToCommons|en.wikipedia}} {{Information |Description={{en|The NIST’s Watt balance. The vacuum chamber dome can be seen above the apparatus. Photo by Richard Steiner}} |Source=Transferred from [http://en.wikipedia.org en.wikipedia]; transferr
The following pages on the English Wikipedia use this file (pages on other projects are not listed):

Global file usage

The following other wikis use this file:

Metadata