Dictionary · Standards & Units
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.
Related terms
More from Standards & Units
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
Numerical value equation
A relation between numerical values that holds only for stated units — the form most spreadsheet formulas quietly are, and the reason unit discipline matters.
VIM (JCGM 200:2012) 1.25
Ordinal quantity-value scale
A quantity-value scale for ordinal quantities, established by agreement on a procedure — comparisons of order are valid, arithmetic on the values is not.
VIM (JCGM 200:2012) 1.28
Quantity of dimension one
A quantity whose dimension has all base-quantity exponents equal to zero — refractive index, strain, a ratio of like quantities; often loosely called "dimensionless".
VIM (JCGM 200:2012) 1.8
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
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