• 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 1Value 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. 2, 1.26)
• Possible comparison of value sets  (a<b, a=b or a>b).

“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). https://www.bipm.org: Bureau International des Poids et Mesures; 2008.