Dictionary · Standards & Units
Base unit
A measurement unit adopted by convention for a base quantity — in the SI: second, metre, kilogram, ampere, kelvin, mole, candela.
Related terms
More from Standards & Units
Quantity
A property of a phenomenon, body, or substance to which a magnitude can be assigned and expressed as a number and a reference (typically a measurement unit).
VIM (JCGM 200:2012) 1.1
Standard reference data
Reference data issued by a recognized authority — the CODATA constants and NIST standard reference databases are the working examples.
VIM (JCGM 200:2012) 5.17
Reference material
Material, sufficiently homogeneous and stable with reference to specified properties, established to be fit for its intended use in measurement or in examination of nominal properties.
VIM (JCGM 200:2012) 5.13
Certified reference material (CRM)
A reference material accompanied by documentation issued by an authoritative body providing property values with uncertainties and traceability using valid procedures — per ISO 17034 practice.
VIM (JCGM 200:2012) 5.14
Intrinsic measurement standard
A standard based on an inherent and reproducible property of a phenomenon or substance — the triple point of water cell, the Josephson voltage standard.
VIM (JCGM 200:2012) 5.10
Kind of quantity
The aspect common to mutually comparable quantities — length, mass, and energy are kinds; diameter and wavelength are both quantities of the kind length.
VIM (JCGM 200:2012) 1.2