Redefined International System of Measurement comes into effect

World Metrology Day has been marked by the start of the redefined International System of Measurement (SI) Units.

Last November, measurement scientists from around the world voted in favour of redefining the SI units. The four base SI units whose redefinition comes into effect today are the:

  • kilogram (measurement of mass)
  • ampere (measurement of electric current)
  • kelvin (measurement of temperature)
  • mole (measurement of substance)

All SI units are now defined in terms of fundamental constants of nature. The National Measurement Institute (NMI) is Australia’s peak body responsible for biological, chemical, physical and trade measurement. As such, it is responsible for providing Australia’s interface with the international measurement system, including Australia’s alignment with the SI revision.

The revision will ensure that the international measurement system is not only robust and able to stand the test of time but able to effectively support future advances in science and technology.

NMI said it is working hard to ensure there will be no disruption to industry. For most, it will appear that not much has changed. The changes, it said, will impact a small number of high level electrical calibration services, but most customers should anticipate a negligible impact.