3. WFD and traceability

3.1 Introduction – Key elements of the traceability concept

Paragraphs 1 and 2 highlighted the importance of data comparability and traceability in the context of WFD monitoring programs. Let's now take a closer look at the various references that need to be considered to establish a reliable metrological system for such analyses.

Firstly, it should be remembered that ISO defines metrological traceability as "the property of a measurement result or standard such that it can be related to specified references, usually national or international standards, through an unbroken chain of comparisons all having specified uncertainties"