Arbitrary threshold concentration (arb.threshold c.) - Dynamic NPU Manual

Arbitrary threshold concentration (arb.threshold c.)


Arb.threshold c.

Definition in words

Arbitrary threshold concentration of component B in system 1 compared with arbitrary threshold concentration of component B in a reference system

Note 1: The reference system is defined by the laboratory.

Result type

Ordinal scale
  • The value set can be either numerical values, characters or words.(The value set and the limit of the value set are defined by the laboratory)

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={+ < ++ < +++}

  • Value set is ranked accoding to magnitude (a<b, a=b or a>b).
  • No algebraic operations among those quantities exist [ref. 2, concept 1.26]



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.


  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.
  2. Mesures BIdPe. International Vocabulary of Metrology – Basic and General Concepts and Associated Terms VIM 3rd edition JCGM 200:2012 (JCGM 200:2008 with minor corrections). Bureau International des Poids et Mesures; 2008.

Laboratory field


Allergology Generic abbreviated form NPU01115 Trcs(B)—Aggregation, thrombin-induced; arb.threshold c.(proc.) = ?
Full form with a result NPU01115 Thrombocytes(Blood)—Aggregation, thrombin-induced; arbitrary threshold concentration(procedure) = Low
Abbreviated form with a result NPU01115 Trcs(B)—Aggregation, thrombin-induced; arb.threshold c.(proc.) = Low
Written expression The arbitrary threshold concentration of Aggregation, thrombin-induced of thrombocytes in Mr. Smith’s blood is [low], compared with arbitrary threshold concentration of Aggregation, thrombin-induced of thrombocytes in a reference system. The measurement is performed according to procedure defined by the laboratory.

The reference system is defined by the laboratory.

“Low” is a value according to a value set defined by the laboratory.

Reference NPU database, and
  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Ordinal kind-of-quantity

        • Arbitrary threshold 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
1996-01-01 Arbitrary threshold concentration Term established