Dictionary · Standards & Units
Primary measurement standard
A standard established using a primary reference measurement procedure, or created as an artifact chosen by convention — not calibrated against another standard for the same quantity.
Related terms
More from Standards & Units
Quantity equation
A mathematical relation between quantities in a system of quantities, independent of units — v = l/t regardless of whether metres or inches are used.
VIM (JCGM 200:2012) 1.22
Measurement standard (etalon)
The realization of the definition of a given quantity, with stated value and uncertainty, used as a reference — an artifact, instrument, reference material, or measuring system.
VIM (JCGM 200:2012) 5.1
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 calculus
The set of mathematical rules applied to quantities rather than bare numbers — the algebra by which units propagate through equations.
VIM (JCGM 200:2012) 1.21
Measurement unit
A real scalar quantity, defined and adopted by convention, with which any other quantity of the same kind is compared to express the ratio of the two quantities as a number.
VIM (JCGM 200:2012) 1.9
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