Concentration (conc.) - Dynamic NPU Manual

Concentration (conc.)



Definition in words

Kind-of-quantity of component B divided by volume of system 1

Note: “Concentration” indicates that the system is a liquid system

Systematic terms

Concentration of component B in system 1

Result type

Ordinal scale
  • Value set is ranked accoding to magnitude
  • The value set and the limit of the value set are defined by the laboratory
  • The value set can be either numerical values or words.

Example 1

Value set={none < some < high < very high}

Example 2

Value set={low < normal< high }

Example 3

Value set={0 < 1 < 2}

Example 4

Value set={negative < positive}

Example 5

Value set={+ < ++ < +++}

  • Algebraic operations are not allowed (Ref. 3, 1.26)
  • Possible comparison of value sets  (a<b, a=b or a>b).

Special rule(s) in the NPU syntax

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

“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.

“?” (placeholder for result) is omitted.


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 form NPU03300 P—Protein type; conc.(list; proc.)
Full result
NPU03300 Plasma—Protein type; concentration(list; procedure)
Abbreviated result  
Written expression  

Thrombosis and Haemostasis

Example 2
Generic abbreviated form NPU28116 B—Fibrinogen; conc.(thrombelastography; list; proc.)
Generic full form NPU28116 B—Fibrinogen; conc.(thrombelastography; list; proc.)
Abbreviated result  
Written expression  


NPU database, and
  • Kind-of-property

    • Concentration


  • 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 Reference
1996-05-09 Concentration Term established NPU database, and
Date Notes


2019-09-20 Concentration has only be limited to list codes, in order to specify whether the system is a liquid system. List codes are headers that describe the property of the patient with a list of measurements (one or more NPU codes). The kinds-of-quantity to the NPU codes may be a mix of kinds-of-quantity, e.g. mass concentration, substance concentration, catalytic concentration, arbitrary concentration etc.  
2019-09-20 The resulttype is not speficied