measurement standard established using a primary reference measurement procedure, or created as an artifact, chosen by convention
measurement standard established using a primary reference measurement procedure, or created as an artifact, chosen by convention
EXAMPLE 1 Primary measurement standard of amount-of-substance concentration prepared by dissolving a known amount of substance of a chemical component to a known volume of solution.
EXAMPLE 2 Primary measurement standard for pressure based on separate measurements of force and area.
EXAMPLE 3 Primary measurement standard for isotope amount-of-substance ratio measurements, prepared by mixing known amount-of-substances of specified isotopes.
EXAMPLE 4 Triple-point-of-water cell as a primary measurement standard of thermodynamic temperature.
EXAMPLE 5 The international prototype of the kilogram as an artifact, chosen by convention.