Dictionary · Standards & Units
Conservation of a measurement standard
The set of operations necessary to preserve the metrological properties of a standard within stated limits — storage, handling, surveillance, and use discipline.
Related terms
More from Standards & Units
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
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
Conversion factor between units
The ratio of two units for quantities of the same kind — 25.4 mm/in; the numerical value changes, the quantity does not.
VIM (JCGM 200:2012) 1.24
System of quantities
A set of quantities together with the non-contradictory equations relating them — the framework a system of units is built on.
VIM (JCGM 200:2012) 1.3
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
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