ADD TO COLLECTION
  • Add to new collection
  • CANCEL
    Rights: Image reproduced with permission of the BIPM, which retains full internationally protected copyright (© BIPM) Published 17 August 2011 Size: 190 KB Referencing Hub media

    The IPK (international prototype kilogram) is housed under three nested glass bell jars with a carefully controlled atmosphere. The IPK was retired on 20 May 2019.