What is traceability?

This term is increasingly used to describe the reliability of measurements. In an absolute sense, it is the gateway to the basic system of measurement units (the International System of Units (SI)) or its derived units. In the International Basic Terminology of Metrology (VIM), traceability is more generally defined as: "The characteristic that a measurement result can be linked to an appropriate standard, usually a national or international standard, through an unbroken chain of comparisons" .