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International temperature scale comparison table
Subject has proposal date has definition has acronym is a kind of
temperature unit A temperature unit is a measure of the average kinetic energy per degree of freedom of the constituent molecules. unit
International temperature scale1927A temperature scale defined between 0.65 K and the highest temperatures practicably measurable in terms of the Planck radiation law using monochromatic radiation. There are 17 fixed temperature points :
  • Below 5 K are defined in terms of the vapour pressures of helium 3 and helium 4
  • Between 5 K and the triple point of water are marked by the triple points of certain elements, e.g. neon (24.5561 K)
  • Above 0.01 °C are defined with reference to the freezing points of specified metallic elements
  • Upper limit is 1064.43 °C (1337.58 K), the freezing point of gold
[JN92] -has source: J. A. Hall, 1967		ITS90temperature unit

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