Life span - Dynamic NPU Manual

Life span


Time, duration, time elapsed, age, life expectancy, time difference

Definition in words

A specific moment of time minus another specific moment of time

Note 1: Time is a SI base kind-of-quantity

Note 2: Component B may be a chemical, biological or physiological proces, e.g. coagulation

Definition by equation

Systematic terms

Life span 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-∞


s (second is the corresponding base measurement unit), h, d (day or 24 hours), m (month), year(s) etc.

Non-recommended term

Period of time


  1. 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.
  2. IUPAC Goldbook homepage.
  3. BIPM homepage.
  4. Lehmann HP, Fuentes-Arderiu X, Bertello L. Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996). Pure and Applied Chemistry. 2009;68(4):957-1000. doi:10.1351/pac199668040957.

Laboratory field


Reproduction and Fertility

Generic abbreviated NPU18843 Sem—Spermatozoa; life span(after ejaculation) = ? h
Full result NPU18843 Semen—Spermatozoa; life span(after ejaculation) = 2 hour
Abbreviated result NPU18843 Sem—Spermatozoa; life span(after ejaculation) = 2 h
Written expression The life span after ejaculation of Spermatozoa in Mr. Smith’s semen is [2] hour.


  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Life span


  • 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
2001-05-22 Life span Term established