International System of Units and SI Units

[The international system of units (SI)].

SI units.

SI Units The International System of Units (SI) is system of units of measurements that is widely used all over the world. This modern form of the Metric system is based around the number 10 for convenience. A set unit of prefixes have been established and are known as the SI prefixes or the metric prefixes (or units). The prefixes indicate whether the unit is a multiple or a fraction of the ba...

Dimensionless units in the SI

The International System of Units (SI) is supposed to be coherent. That is, when a combination of units is replaced by an equivalent unit, there is no additional numerical factor. Here we consider dimensionless units as defined in the SI, e.g. angular units like radians or steradians and counting units like radioactive decays or molecules. We show that an incoherence may arise when different un...

SI units and anticonvulsant drugs in paediatrics.

The concept of using SI units has now been accepted in principle by most medical practitioners in the United Kingdom, and laboratories now report most of their results in these units. During the transition period the use of conversion nomograms such as those produced by Baron' and Bold and Wilding2 have proved invaluable in helping both clinician and laboratory worker to adjust to new reference...

Mise en pratique for the definition of the candela and associated derived units for photometric and radiometric quantities in the International System of Units (SI)