Dictionary · Standards & Units
Coherent system of units
A system of units in which every derived unit is coherent — the SI as used with its base and coherent derived units.
Related terms
More from Standards & Units
Conservation of a measurement standard
The set of operations necessary to preserve the metrological properties of a standard within stated limits — storage, handling, surveillance, and use discipline.
VIM (JCGM 200:2012) 5.11
Numerical quantity value
The number in a quantity value — the 5.34 in 5.34 m: the ratio of the quantity to its unit.
VIM (JCGM 200:2012) 1.20
International System of Quantities (ISQ)
The system of quantities based on the seven base quantities: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity — the quantity framework beneath the SI.
VIM (JCGM 200:2012) 1.6
Derived unit
A measurement unit for a derived quantity, formed as a product of powers of base units — the newton (kg·m·s⁻²) or the pascal (N/m²).
VIM (JCGM 200:2012) 1.11
System of units
A set of base and derived units, with their multiples and submultiples, defined under given rules for a given system of quantities.
VIM (JCGM 200:2012) 1.13
Base unit
A measurement unit adopted by convention for a base quantity — in the SI: second, metre, kilogram, ampere, kelvin, mole, candela.
VIM (JCGM 200:2012) 1.10