Relative viscosity (rel.visc.) - Dynamic NPU Manual

Relative viscosity (rel.visc.)


Viscosity ratio



Definition in words

Dynamic viscosity of component B in system 1 divided by dynamic viscosity of component B in system 2

Note: System 1 is not related to system 2

Definition by equation

Systematic terms

Relative viscosity of component B in system 1

Result type

Rational scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞


10-6, 10-3, 1 (one), 103, 106, etc.

The unit “1” (one) is ommited in the NPU syntax.


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.

Laboratory field


Clinical Chemistry

Generic abbreviated
NPU18995 P—Plasma; rel.visc.(37 °C/water, 37 °C) = ?
Full result NPU18995 Plasma—Plasma; relative viscosity(37 °C/water, 37 °C) = 2.5 x one
Abbreviated result NPU18995 P—Plasma; rel.visc.(37 °C/water, 37 °C) = 2.5
Written expression The relative viscosity of Mr. Smith Plasma is [2.5]. The calculation is performed by dividing the viscosity of Mrs. Smith’s Plasma with the viscosity of waterThe measurements in plasma and water are performed at 37 °C.


NPU database, and
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Relative viscosity


  • 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
2001-01-01 Relative viscosity Term established