World Metrology Day

Celebrating World Metrology Day and the start of the redefined International System of Measurement (SI) Units.
Photo of the International Prototype Kilogram, the original ‘master kilogram’.

International Prototype Kilogram, the original ‘master kilogram’. Image credit: International Bureau of Weights and Measures.

Today is World Metrology Day, a day dedicated to raising awareness about the importance of measurement. Life as we know it is measured in units like the second, metre and kilogram. Science, trade and industry all rely on accurate measurement to function and produce results.

Today also marks 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. Four base SI units will be redefined today:

  • 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 revision will ensure that the international measurement system is robust and able to stand the test of time. It will also effectively support future advances in science and technology.

What it means for Australia

The National Measurement Institute (NMI) is Australia’s peak body responsible for biological, chemical, physical and trade measurement. It is responsible for providing Australia’s interface with the international measurement system, including Australia’s alignment with the SI revision.

NMI is working hard to ensure there will be no disruption to industry. For most, it will appear that not much has changed. The changes will impact a small number of high level electrical calibration services, but most customers using our calibration services can anticipate a negligible impact. Companies using our measurement and calibration services can expect a seamless transition.

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Email communications@measurement.gov.au