Arbitrary logarithmic number concentration (arb.log.num.c) - Dynamic NPU Manual

Arbitrary logarithmic number concentration (arb.log.num.c)

Abbreviation

Arb.log.num.c

Definition in words

Logarithm of the arbitrary number concentration of component B in system 1

Definition by equation

 

Result type

Ratio 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 ratio scale is attributed to the NPU definition, the unit is a non-SI unit.

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.

 

Laboratory field

Examples

Clinical Microbiology

Example 1
Generic abbreviated form NPU57952 P—Cytomegalovirus(DNA); arb.log.num.c.(proc.) = ? (p.d.u.)
Full form with a result NPU57952 Plasma—Cytomegalovirus(DNA); arbitrary logarithmic number concentration(procedure) = 10 logs
Abbreviated form with a result NPU57952 P—Cytomegalovirus(DNA); arb.log.num.c.(proc.) = 10 logs
Written expression The arbitrary logarithmic number concentration of Cytomegalovirus(DNA) in Mr Smith’s plasma is [10] logs. The measurement is performed according to a procedure defined by the given laboratory.
Equation
Notes “Logs” was chosen by a local laboratory as a proprietary measurement unit and not an accepted international unit.
Example 2
Generic abbreviated form NPU58454 Csf—Tick-borne encephalitis virus(RNA); arb.log.num.c(proc.) = ? (p.d.u.)
Full form with a result NPU58454 Cerebrospinal fluid—Tick-borne encephalitis virus(RNA); arbitrary logarithmic number concentration(procedure) = 0.2 log unit
Abbreviated form with a result NPU58454 Csf—Tick-borne encephalitis virus(RNA); arb.log.num.c(proc.) = 0.2 log unit
Written expression The arbitrary logarithmic number concentration of Tick-borne encephalitis virus(RNA) in Mr Smith’s cerebrospinal fluid is [0.2] log unit. The measurement is performed according to a procedure defined by the given laboratory.
Equation
Notes “Logs” 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/ and http://www.labterm.dk/default.aspx
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Logarithmic differential unitary kind-of-quantity

          • Arbitrary logarithmic 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
2017-12-15 Arbitrary logarithmic number concentration Term established