Traceability-the national roles

Traceability is defined as a process whereby a measurement is compared to national standards by an unbroken chain of comparisons. The author discusses a traceability hierarchy in the UK which puts the industrial base as being supported by a number of calibration laboratories which in turn are supported by a standards laboratory. The traceability hierarchy has within it the Services Electric Standards Centre (SESC) which has a role as the Master Reference Laboratory and as such acts as a major interface between the standards laboratory and the other NAMAS Accredited Laboratories. The SESC has a long history of RF and microwave metrological work and has made a significant contribution to the expertise in this field. The other feature of the traceability hierarchy in the UK since 1967 is the National Measurement Accreditation Service (NAMAS) (formerly British Calibration Service) whose role is that of assessing all of the technical aspects of a laboratory's practices in regard to accreditation for specific tests or calibrations.<>