EXAMPLE Human serum with assigned quantity value for the concentration of cholesterol and associated measurement uncertainty stated in an accompanying certificate, used as a calibrator or measurement trueness control material.

NOTE 1 'Documentation' is given in the form of a 'certificate' (see ISO Guide 31:2000).

NOTE 2 Procedures for the production and certification of certified reference materials are given, e.g. in ISO Guide 34 and ISO Guide 35.

NOTE 3 In this definition, “uncertainty” covers both 'measurement uncertainty' and 'uncertainty associated with the value of a nominal property', such as for identity and sequence. “Traceability” covers both 'metrological traceability of a quantity value' and 'traceability of a nominal property value'.

NOTE 4 Specified quantity values of certified reference materials require metrological traceability with associated measurement uncertainty (Accred. Qual. Assur.:2006) ^[45].

NOTE 5 ISO/REMCO has an analogous definition (Accred. Qual. Assur.:2006) ^[45] but uses the modifiers “metrological” and “metrologically” to refer to both quantity and nominal property.