» Important Announcement for UKAS Accredited Calibration Laboratories

23 April, 2010

BMC to CMC - A change in terminology from Best Measurement Capability to Calibration and Measurement Capability

The measurement capabilities provided by UKAS calibration laboratories have in the past been described by the Best Measurement Capability (BMC) which expresses the lowest uncertainty of measurement that could be achieved during a calibration. This terminology has been widespread in accreditation around the world.

The National Metrology Institutes (NMIs) have used a similar description of the services provided to their clients. Within the NMI community the term has been Calibration and Measurement Capability (CMC).

In pursuit of harmony and co-operation between the communities, ILAC has decided to make a change in the terminology used and in the future the BMC will be named as the CMC.

Your Schedule showing your Best Measurement Capability will be amended by UKAS to read Calibration and Measurement Capability and the schedule will be up-issued. This change is of the terminology only, as BMC and CMC have been agreed to be equivalent. There are no technical implications regarding schedules, uncertainty budgets, capabilities or assessments.

UKAS will implement this change in terminology by 31 December 2010.

No immediate action is required by accredited laboratories but you should now phase out any mention of BMC and replace it with CMC in advertisements and other literature. The certificates you issue are not affected as these describe the Uncertainty of Measurement of the particular calibration undertaken. UKAS will be revising the document M3003 as it contains references which will be to the CMC. Laboratories should advise their customers of the equivalence of the terms BMC and CMC and should assure customers that there is neither practical difference nor any other implication from this change in terminology.

The regime for the ongoing assessment of your laboratory, and of your uncertainty budgeting, remains unaffected by this change.

A Questions and Answers sheet for laboratories together with the ILAC Circular and the EA announcement are included as links at the bottom of this page. Please refer any remaining queries to your UKAS Assessment Manager or to Trevor Thompson, UKAS Accreditation Manager for EPT Section (Tel: 020 8917 8476 / Email: trevor.thompson@ukas.com)