Volume rate (vol.rate) - Dynamic NPU Manual

Volume rate (vol.rate)


Volume flow rate, mean volume rate, volume rate of flow



Definition in words

Change of volume of component B divided by the difference of time in system 1

Definition by equation

Result type

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


µL/s, ml/s, L/min, etc.

Non-recommended term

Volume flux, flux, flow, discharge, flow rate, discharge rate, volume per unit time


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

Example 1
Generic abbreviated
NPU28812 Kidn.—Glomerular filtration; vol.rate = ? mL/min
Full result NPU28812 Kidneys—Glomerular filtration; volume rate = 120 mL/min
Abbreviated result NPU28812 Kidn.—Glomerular filtration; vol.rate = 120 mL/min
Written expression The volume rate of Glomerular filtration of Mr. Smith’s kidneys is [120] mL/min
Example 2
Generic abbreviated
NPU18284 Pt—Urine; vol.rate = ? L/d
Full result NPU18284 Patient—Urine; volume rate = 2.5 L/d
Abbreviated result NPU18284 Pt—Urine; vol.rate = 2.5 L/d
Written expression The volume rate of Mr. Smith‘s Urine is [2.5] L/d


NPU database, https://www.ifcc.org/ifcc-scientific-division/sd-committees/c-npu/npusearch/ and http://www.labterm.dk/default.aspx
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Volume rate


  • 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 Volume rate Term established