• DocumentCode
    1502816
  • Title

    Consider the kilogram

  • Author

    Courtland, Rachel

  • Volume
    49
  • Issue
    5
  • fYear
    2012
  • fDate
    5/1/2012 12:00:00 AM
  • Firstpage
    34
  • Lastpage
    39
  • Abstract
    Once a year, three officials bearing three separate keys meet at the bottom of a stairwell at the International Bureau of Weights and Measures, in Sevres, France. There they unlock a vault to check that a plum-size cylinder of platinum iridium alloy is exactly where it should be. Then they close the vault and leave the cylinder to sit alone, under three concentric bell jars, as it has for most of the past 125 years.
  • Keywords
    indium alloys; platinum alloys; units (measurement); concentric bell jars; kilogram; platinum iridium alloy; plum-size cylinder; separate keys; vault; Atomic measurements; Measurements; NIST; Standards;
  • fLanguage
    English
  • Journal_Title
    Spectrum, IEEE
  • Publisher
    ieee
  • ISSN
    0018-9235
  • Type

    jour

  • DOI
    10.1109/MSPEC.2012.6189573
  • Filename
    6189573
    • Link To Document
    https://search.isc.ac/dl/search/defaultta.aspx?DTC=49&DC=1502816