METROLOGY IN CHEMISTRY

摘要

A measurement is an experimental process by which a specific value of a physical quantity is determined as the multiple of a unit. From this it follows that we need a system of units to be able to measure the different quantities, length, mass, and time, for example. Such a system exists. It is the International System of Units (Systeme International d'Unites, SI). It comprises at present seven base units: metre, kilogram, second, ampere, kelvin, mole and candela. It was adopted and recommended for use in 1971 by the General Conference, on Weights and Measures (Conference Generale des Poids et Mesures, CGPM).