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Institute for Reference Materials and Measurements (IRMM)Geel, Belgium

http://www.irmm.jrc.behttp://www.jrc.cec.eu.int

The CMC processUlf Jacobsson

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The metrological world

• Scientific leg– BIPM, RMOs, NMIs

– MRA, CMC

• Accreditation leg– ILAC, RABs, NABs

– MRA/MLA

• Legal leg– OIML, RLMOs (for example WELMEC)

– MAA, DoMC

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What is then CMC?

• Calibration and Measurement Capability as defined in the Mutual Recognition Agreement (MRA)

• Set up in a database att BIPM

• The Key Comparison Data Base (KCDB) annex C contains the current CMC tables submitted by national laboratories.

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Rules of procedure 1

1. NMI sends draft CMCs to TC/WG for review and approval according to the JCRB and RMO criteria.

2. RMO representative posts the approved CMCs.

3. Forwards of the posted CMCs to the TC/WG Chairs in the same area, to the RMO representatives and to the Executive Secretary of the JCRB.

4. RMO Representatives from reviewing RMOs indicate on the interactive website whether or not they will review these CMCs and set a date for completion of the review. RMOs which do not indicate a date for sending comments six weeks after the CMCs are posted relinquish their right to continue the review.

5. RMO Representatives from reviewing RMOs post their first comments in the website by the set date. RMOs who do not send their comments within six weeks after the date indicated relinquish their right to continue the review.

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Rules of procedure 26. The website automatically forwards the received comments to all other reviewing

TC/WG Chairs, to the RMO representatives and to the Executive Secretary of the JCRB.

7. After the first comment is posted in the website, inter-regional review takes place which includes direct contact between TC/WG Chairs of originating and reviewingRMOs. Technical contacts who wish to do so may use the JCRB website to post and distribute their comments.

8. NMIs revise their CMCs as necessary and re-submit to local RMO.9. The RMO Representative from the originating RMO posts the revised CMCs in the

website for final approval10.The website automatically forwards the posted CMCs to the reviewing TC/WG

Chairs, to the RMO representatives and to the Executive Secretary of the JCRB.11.RMO Representatives indicate their approval in the website or send additional

comments if they still have concerns. RMOs who do not indicate their decision six weeks after the CMC file is posted relinquish their right to vote on that file.

12.Provided all eligible RMOs indicate their approval, the CMCs are entered into Appendix C. Noted on the website with date of entry.

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Flow chart intra regional process

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Flow chart inter regional process

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Flow chart inter regional process

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Approval and pub process

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Procedure for modifying CMCs already in Appendix C

Modifications of a published CMC usually arise for reasons falling into one of three categories:

1. Material or editorial errors and improvements to the explanatory text for a quantity, instrument, method etc.

2. Increase of the uncertainty or reduction in scope, decided by the NMI or following a comparison result.

3. Change of the method of measurement or reduction of the uncertainty or increase in scope.

For category 1 and 2 no RMO-review is necessary

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Chain of responsibility1.NMI making the CMC claim has primary and principal responsibility.

2.Through its TC/WG, the RMO should monitor the impact of key and supplementary comparison results on CMC claims for its member NMIs.

3.The Consultative Committee Working Groups on CMCs are intended to: • provide guidance on the range of CMCs supported by particular key and

supplementary comparisons (KC and SC);

• identify areas where additional KCs and SCs are needed; and

• coordinate the review of existing CMCs in the context of new results of KC and SC

4.If, based on the results of a key or supplementary comparison, an RMO/NMI has concerns about the CMC claims of a particular NMI within another RMO, it should contact the NMI directly to seek resolution. If this is not successfully concluded, then the matter should be directed to the relevant RMO of the NMI making the CMC claims. In the event that further intervention is required, the JCRB Chairman should then be requested to help resolve the issue.

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Criteria for acceptance 1

1. Results of key and supplementary comparisons

2. Documented results of past CC, RMO or other comparisons (including bilateral)

3. Knowledge of technical activities by otherNMIs, including publications

4. On-site peer-assessment reports

5. Active participation in RMO projects

6. Other available knowledge and experience

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Criteria for acceptance 2

• While the results of key and supplementary comparisons are the ideal supporting evidence, all other sources may be considered to underpin CMCsnot directly related to the available comparison results and those for which comparison results are not yet available.

• The NMIs that issue the CMCs are primarily responsible for providing, through their local TC/WGs, the information that they believe is necessary to support their claims. TC/WGs from other RMOs may request additional information, if needed.

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General rules for accepting CMCs

• Technical support for the arrangement, as stated in Section 3 of the MRA, is achieved mainly through the results of key and supplementary comparisons. Confidence in measurements is further obtained by the presence of some means of assuring quality, as indicated in the MRA Section 7.3.

• Key comparisons are designed to provide evidence on the proficiency of NMIs in the principal techniques in each field. They are selected, conducted and evaluated by the CIPM Consultative Committees (CCs). Supplementary comparisons are undertaken independently by RMOs when CMCs require additional support not provided by key comparisons.

• While it is important that each CMC submission is supported by some comparison evidence, it is not the intention of the MRA to have a one-to-one correspondence between CMCs and comparisons. A key or a supplementary comparison may provide enough evidence to underpin the uncertainty claims of a group of related CMCs. How broad this group should be is an issue being considered by the CCs on a continuing basis.

• In addition to comparison results, the criteria for acceptance of data for Appendix C lists a number of different possible sources of information that can be used to support CMC claims.

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BIPM intervention on CMC files

Criteria Reference Doc.Spelling and format JCRB-6/6 etc.

CMC range and uncer-tainty specification JCRB-12/6

NMI listing in Appendix A MRA chapter 1

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CMC review summary

• A claim is filed by the NMI to its TC/WG• The claim is then reviewed locally in the RMO• If not found supported the claim will remain in review

loop in local RMO.• After getting acceptance the claim is forwarded to

other RMOs.• The claim is then returned with comments from the

RMOs• If the decision is favourable an updated post will occur

in the KCDB• BIPM can intervene in CMC files given special criterias

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Reference listText from the following documents was used• JCRB Rules of Procedure JCRB-14/06(1)

• Flow Charts JCRB-12/06a_rev 2004-05-14

• Procedure for modifying CMCs already in Appendix C JCRB-8/10_rev 2004-09-11

• The chain of responsibility JCRB-11/7(a)

• Criteria for acceptance of data JCRB-14/06(2a)_final

• General rules for accepting CMCs JCRB-11/6(3)

• BIPM Interventions JCRB-12/06(3)

All documents above are available on:

http://www.bipm.org/en/committees/jc/jcrb/documents.html

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Use of the MRA logotype

• Some NMIs are authorized to use the MRA logotype.

• Why not all those who have their CMC tables accepted?

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Intra-Inter regional reviews

RMOs define their own procedures to carry out intra regional CMC reviews.

Once the CMCs are approved at the regional level, the TC/WG Chairperson sends them to the RMO representative, who in turn submits them to the JCRB for inter-regional review