Traceability
Traceability
Traceability is the property of a measurement result to be linked to national or international standards through an unbroken chain of calibrations. Thanks to it, a millimetre you measure means the same as a millimetre anywhere else in the world. Calibration is the means by which traceability is achieved.
The chain starts from the international definitions of the units (SI) and the national standards held by the national metrology institutes, and comes down step by step. Each link must be calibrated against the previous one, with no gaps· if even a single link breaks, traceability is lost.
In practice, traceability is what makes measurements comparable and accepted everywhere: between supplier and customer, across different factories or countries, and in cases of dispute or audit. Without it, every number would hold only locally.