Arbitrary reciprocal number concentration (arb.recip.num.c.) - Dynamic NPU Manual

Arbitrary reciprocal number concentration (arb.recip.num.c.)

by | Aug 24, 2025 | List of kinds-of-property, Kind-of-quantity

Arbitrary reciprocal number concentration (arb.recip.num.c.)

Abbreviation

 Arb.recip.num.c.

Definition in words

 Volume of system 1 divided by arbitrary number of component B

Definition by equation

Note: kprocedure is a constant defined by the measurement procedure (there is an approximately proportionality to a kind-of-quantity from the International System of Quantities).

Result type

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

Unit

 International unit (IU) or procedure defined unit (p.d.u.) (non-SI units)

Special rule(s) in the NPU syntax

“Procedure” is stated in the specification to the kind-of-property in the NPU definition.

“Procedure” indicates that the measurement procedure must be stated somewhere else than the NPU code and there may be difficulties in comparing values for the same NPU code.

If the unit is an International Unit (IU), an international certified reference material (e.g. WHO reference material) is specified in the specification to the kind-of-property.

If there exist no international certified reference material, the laboratory can specify the unit at the placeholder, procedure defined unit.

Reference

 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

Examples

Microbiology

 
 Generic abbreviated
 NPU60463 U(spec.)—Mycoplasma genitalium(DNA); arb.recip.num.c.(proc.) = ? (p.d.u.)
Full result NPU60463 Urine(specification)—Mycoplasma genitalium(DNA); arbitrary reciprocal number concentration(procedure) = ? 100 L/arbitrary unit
Abbreviated result NPU60463 U(spec.)—Mycoplasma genitalium(DNA); arb.recip.num.c.(proc.) = 100 L/arbitrary unit
Written expression

The arbitrary reciprocal number concentration of Mycoplasma genitalium(DNA) in Mr Smith’s urine is [100] L/arbitrary unit.
Equation

 Notes
 “Arbitrary unit” was chosen by a local laboratory as a proprietary measurement unit.and not an accepted international unit.

Reference
NPU database, https://www.ifcc.org/ifcc-scientific-division/sd-committees/c-npu/npusearch/

  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Arbitrary reciprocal number concentration

Reference
  • 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
2021-11-01 Arbitrary reciprocal number concentration Term established

NPU term identifier

 QU114275