Reference material (RM):
material, sufficiently homogeneous and stable with respect to one or more specified properties, which has been established to be fit for its intended use in a measurement process
NOTE 1 RM is a generic term.
NOTE 2 Properties can be quantitative or qualitative, e.g. identity of substances or species.
NOTE 3 Uses may include the calibration of a measurement system, assessment of a measurement procedure, assigning values to other materials, and quality control.
NOTE 4 A single RM cannot be used for both calibration and validation of results in the same measurement procedure.
NOTE 5 VIM has an analogous definition (ISO/IEC Guide 99:2007, 5.13), but restricts the term "measurement" to apply to quantitative values and not to qualitative properties. However, Note 3 of ISO/IEC Guide 99:2007, 5.13, specifically includes the concept of qualitative attributes, called "nominal properties".
ISO-Guides 30