metrological traceability

Metrological traceability is a property of a measurement result that relates it to a stated reference through a documented sequence of calibrations, each contributing to measurement uncertainty. The reference may be a recognized measurement standard, a reference measurement procedure, or another appropriate stated reference. Traceability belongs to a result in a defined measurement system, not simply to an instrument because it carries a calibration sticker.

Laboratories often rely on manufacturer information about calibrator value assignment and the relevant traceability chain. Examine whether that information applies to the actual measurand, procedure, and materials in use. Where higher-order references are unavailable, understand the limitations of the available reference system. Maintaining traceability also requires suitable calibration practices, records, and management of changes that could interrupt the documented relationship.

Accreditation assessment uses traceability evidence to examine the comparability and reliability of measurement results. Keep relevant certificates, manufacturer statements, and calibration records accessible, and review their scope rather than filing them without evaluation. Traceability does not eliminate uncertainty or guarantee clinical agreement between different procedures, especially where methods measure different forms of the same substance.