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Le Système international d'unités (SI)

The International System of Units (SI)

Introduction to SI

The International System of Units (SI) consists of seven base units that were adopted worldwide by the General Conference on Weights and Measures (...

The Kilogram

In November 2018, the General Conference on Weights and Measures (CGPM) made the decision to modify the definition for the unit of mass. It will no ...

The Meter

From the length of the King’s foot under the Ancien Régime to the notion of a quarter meridian adopted during the French Revolution, to the speed ...

The Second

As the unit for measuring time, the second is currently defined with reference to a property of matter: the radiation period of a cesium atom. Once an...

The Ampere

Along with the ohm and the volt, the ampere is one of the three base units in the field of electricity. It was adopted as a base unit in the ...

The Kelvin

Temperature is one of the most commonly used quantities in our day-to-day life, and it’s measured in countless industrial processes. Ever since it ...

The Mole

In 1971, the mole – the unit of measurement for amounts of a substance – became the last of the seven units to be integrated into the ...

The Candela

From flashlights to LED lights, candles, incandescent bulbs and fluorescent tubes, lighting has been essential to human survival, safety and well-...