Dictionary · Standards & Units
Commutability of a reference material
The property demonstrated by the closeness of agreement between the relation among results for a stated quantity in the RM and the relation among results for representative routine samples, across specified procedures — whether the RM behaves like the real thing.
Related terms
More from Standards & Units
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
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
Conversion factor between units
The ratio of two units for quantities of the same kind — 25.4 mm/in; the numerical value changes, the quantity does not.
VIM (JCGM 200:2012) 1.24
International measurement standard
A standard recognized by signatories to an international agreement and intended to serve worldwide.
VIM (JCGM 200:2012) 5.2
Multiple of a unit
A unit obtained by multiplying a given unit by an integer greater than one — the kilometre from the metre.
VIM (JCGM 200:2012) 1.17
Quantity value
A number together with a reference (such as a measurement unit) expressing the magnitude of a quantity — 5.34 m, 0.152 kg, or a value on an agreed scale.
VIM (JCGM 200:2012) 1.19