Relative time (rel.time) - Dynamic NPU Manual

Relative time (rel.time)



Definition in words

Time of component B in system 1 divided by time of component B in system 2

Note: System 1 is not related to system 2

Definition by equation

Systematic terms

Relative time 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


Thrombosis and Haemostasis

Generic abbreviated
NPU01681 P—Coagulation, surface-induced; rel.time(actual/norm; proc.) = ?
Full result NPU01681 Plasma—Coagulation, surface-induced; relative time(actual/norm; procedure) = 0.95 x one
Abbreviated result NPU01681 P—Coagulation, surface-induced; rel.time(actual/norm; proc.) = 0.95
Written expression The relative time of surface-induced Coagulation in Mrs. Smith’s Plasma is [0.95]. The calculation is performed by dividing the time of surface-induced Coagulation in Mr. Smith’s Plasma (actual) with the time of surface-induced Coagulation in a norm (reference system)The measurement is performed according to procedure defined by the laboratory.


“Actual” refers to the Mr. Smith’s result. “Norm” is a reference system that is defined by the laboratory.


  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Relative time


  • 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 Relative time Term established