Traceability

Abstract

Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty (JCGM 200:2012 International Vocabulary of Metrology, Clause 2.41). Note 1 For this definition, a “reference” can be a definition of a measurement unit through its practical realization or a measurement procedure including the measurement unit for a non-ordinal quantity or a measurement standard. Note 2 Metrological traceability requires an established calibration hierarchy. Note 3 Specification of the reference must include the time at which this reference was used in establishing the calibration hierarchy, along with any other relevant metrological information about the reference, such as when the first calibration in the calibration hierarchy was performed. Note 4 For measurements with more than one input quantity in the measurement model, each of the input quantity values should itself be metrologically traceable, and the calibration hierarchy involved may form a branched structure or a network. The effort involved in establishing metrological traceability for each input quantity value should be commensurate with its relative contribution to the measurement result.