History of the metric system levels of the krypton 86 atom as the new standard for the metre. The standard metre artefact was retired. In 1960, Giorgi's proposals were adopted as the basis of the "Système International d'Unités" (International System of Units), the SI. This initial definition of the SI included six base units, the metre, kilogram, second, ampere, degree Kelvin and candela, and sixteen coherent derived units. The evolution of the SI after its publication in 1960 has seen the addition of a seventh base unit, the "mole", and six more derived units, the "pascal" for pressure, the "gray", "sievert" and "becquerel" for radiation,
Lambda (unit) mL (a unit 1000 times larger). In pharmaceutical use, no abbreviation for a microlitre is considered safe. The recommended practice is to write "microlitre" in full. Lambda (unit) Lambda (written λ, in lowercase) is a non-SI unit of volume equal to 10m, 1 cubic millimeter (mm) or 1 microlitre (µL). Introduced by the BIPM in 1880, the lambda has been used in chemistry and in law for measuring volume, but its use is not recommended. This use of λ parallels the pre-SI use of µ on its own for a micrometre and γ for a microgram. Although the use of