Entitic volume difference (entitic vol.diff.) - Dynamic NPU Manual

Entitic volume difference (entitic vol.diff.)


Entitic vol.diff.

Definition in words

Difference of entitic volume of component B at different conditions in system 1

Definition by equation

Systematic terms

Entitic volume difference of component B in system 1
Ratio scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞


fL, pL, µL, etc.

Note: The correct unit is e.g. “µm/1” but “1” is omitted.

Special rule(s) in the NPU syntax

The different conditions must be specified in the specification to kind-of-property


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.

Laboratory field


Clinical Chemistry

Generic abbreviated
NPU18615 B—Thrombocytes; entitic vol.diff.(max.-min.; PDW; proc.) = ? fL
Full result NPU18615 Blood—Thrombocytes; entitic volume difference(maximum-minimum; PDW; procedure) = 4 femtolitre
Abbreviated result NPU18615 B—Thrombocytes; entitic vol.diff.(max.-min.; PDW; proc.) = 4 fL
Written expression The entitic volume of Thrombocytes in Mr. Smith’s blood is [4] fL. The calculation is the difference between the thrombocyte with the maximum volume and the thrombocyte with the minimum volume. Also called Platelet Distribution Width (PDW). The measurement is performed according to procedure defined by the laboratory.


  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Entitic volume difference


  • Dybkaer R. Concept system on ‘quantity’: formation and terminology. Accredit Qual Assur. 2013;18(3):253-60.
  • Dybkaer R. ISO terminological analysis of the VIM3 concepts ‘quantity’ and ‘kind-of-quantity’. Metrologia. 2010;47(3):127-34.
Date Term Note
1996-01-01 Entitic volume difference Term established