Kind-of-quantity of dimension one - Dynamic NPU Manual

Content (cont.)

Synonym Dimensionless kind-of-quantity
Definition by words

Quantity for which all the exponents of the factors corresponding to the base quantities in its quantity dimension are zero


The measurement units and values of quantities of dimension one are numbers, but such quantities convey more information than a number.

Some quantities of dimension one are defined as kind-of-quantity divided by the same kind-of-quantity

The mathematical equation is:

Examples are: mass fraction, substance ratio

Other kinds-of-quantity of dimension one that may not be defined as above is Numbers of entities.

  1. International Vocabulary of Metrology – Basic and General Concepts and Associated Terms (VIM 3rd edition)
    JCGM 200:2012
  3. 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.