Dictionary · Standards & Units
System of quantities
A set of quantities together with the non-contradictory equations relating them — the framework a system of units is built on.
Related terms
More from Standards & Units
Working measurement standard
A standard used routinely to calibrate or verify instruments or systems, itself usually calibrated against a reference standard.
VIM (JCGM 200:2012) 5.7
Travelling measurement standard
A standard, sometimes of special construction, intended for transport between locations — the artifacts that carry interlaboratory comparisons.
VIM (JCGM 200:2012) 5.8
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
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
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
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