Dictionary · Standards & Units
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.
Related terms
More from Standards & Units
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
Quantity-value scale
The ordered set of values that quantities of a given kind may take — the scale a thermometer or hardness tester reports on.
VIM (JCGM 200:2012) 1.27
System of units
A set of base and derived units, with their multiples and submultiples, defined under given rules for a given system of quantities.
VIM (JCGM 200:2012) 1.13
Coherent derived unit
A derived unit that is a product of powers of base units with no numerical factor other than one — the newton is coherent in the SI; the kilometre per hour is not.
VIM (JCGM 200:2012) 1.12
Derived unit
A measurement unit for a derived quantity, formed as a product of powers of base units — the newton (kg·m·s⁻²) or the pascal (N/m²).
VIM (JCGM 200:2012) 1.11
Unit equation
A mathematical relation between base and derived units — N = kg·m·s⁻².
VIM (JCGM 200:2012) 1.23