Arbitrary (arb.) - Dynamic NPU Manual

Arbitrary (arb.)

Abbreviation Arb.
Definition Based on random choice or personal whim, rather than any reason or system
Scope “Arbitrary” is a modifier (adjective) to a kind-of-quantity.
Description Arbitrary indicates that the kind-of-quantity is outside the International System of Quantities, i.e., as for kind-of-property. The corresponding measurement unit to the arbitrary kind-of-quantity has no dimension within the SI measurement unit.
Reference Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. doi:10.1039/9781782622451.
Amount-of-substance Arbitrary amount-of-substance
Catalytic-activity Arbitrary catalytic-activity
Date Subject
2020-06-07 “Arbitrary” was added to the NPU terminology due to the need of kind-of-property and measurement units that were and could not be defined by the International System of Quantities and International System of Units. The greatest caveeat using arbitrary kinds-of-property and arbitrary measurement units is that they cannot be compared without subtantial more information about the methods and their traceability to the primary method.