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Chemistry International

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Volume 41, Issue 2


Bye-Bye, IPK!

Daniel Rabinovich
Published Online: 2019-04-01 | DOI: https://doi.org/10.1515/ci-2019-0221


The International Prototype Kilogram, after 130 years of dutiful service, is finally retiring. The IPK, a golf ball-sized cylinder made of a special platinum-iridium alloy (90:10), was introduced in 1889 at the first General Conference on Weights and Measures (CGPM) near Paris to define the unit of mass using an artifact fabricated with the utmost care and precision available at the time. New units were subsequently adopted for other physical quantities such as electric current (the ampere) and temperature (the kelvin), and the increasing need for a more cohesive set of units of measurement led to the implementation of the International System of Units (SI) in 1960.

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Published Online: 2019-04-01

Published in Print: 2019-04-01

Citation Information: Chemistry International, Volume 41, Issue 2, Pages 53–54, ISSN (Online) 1365-2192, ISSN (Print) 0193-6484, DOI: https://doi.org/10.1515/ci-2019-0221.

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