The SI System is Revolutionized!

weight SI KilogramOld Style weights. Photo:

Theme Day 24 May: The SI System is Revolutionized!

The kilogram as we know it is to be redefined. The weight in Paris is no longer be the definition of one kilogram, as of now it will be connected to constants in nature just like the other SI units are.


When the kilogram is redefined, other SI devices will follow. At the General Conference for Measures and Weights to be held in November this year, the revised SI system is being adopted effective as of the World Metrology Day, May 20th, 2019.

But if the kilogram is not a weight – what then?

The new definition will open for several different methods to measure a kilogram. One of these methods is the “Kibble balance” which measures electromagnetic force against gravity’s impact on an object. This gives you a readable voltage that you can use to define the mass of the object.

The Norwegian Metrology Service (NMS) has based on a recipe from National Institute of Standards and Technology (NIST), built a functional lego model of the Kibble balance, aka the Watt balance. Marit Ulset Nordsveen bruker denne til å forklare prinsippet.

What now?

What are the implications of the altered SI systems for how we measure? Does it mean we have to re-measure the world? The Norwegian Metrology Service (Justervesenet) invites to a theme day on the upcoming changes to the SI system. On Thursday May 24th, NMS professionals will talk about the changes, as well as other topics related to measurements.


© Justervesenet / #Norway Today