At its 15th meeting, the Consultative Committee for Time and Frequency (CCTF) decided to designate the comparison organized by the BIPM that is used to establish International Atomic Time (TAI) and Coordinated Universal Time (UTC) as the CCTF key comparison in Time, identified in the KCDB as CCTF-K2001.UTC, and with UTC as the key comparison reference value. It is a continuous one, producing data every five days with monthly updates.

Results of CCTF-K2001.UTC are published in the KCDB through a link to Circular T. It provides the offsets with respect to UTC of 56 time laboratories, 34% of whom are not yet participating in the CIPM MRA. Work is in progress at the BIPM Time section to assign uncertainties to these offsets.

The CCTF Working Group on the CIPM MRA issued a Classification of Services for drawing up CMCs files in Time and Frequency. This was agreed among the RMOs and approved by the CCTF in 2003. No CMCs on Time and Frequency have yet been published in the KCDB Appendix C, but some hundreds declared by APMP, COOMET and EUROMET have been forwarded to the JCRB and are currently under inter-regional review process.

  The time

Some 70 Directors of national metrology institutes (NMI) from Members of the Metre Convention and from Associates of the General Conference on Weights and Measures met at the BIPM on 30 September and 1 October 2004. There was a full agenda which included a presentation from Dr Janko Drnovšek (MIRS, Slovenia) on his experience of implementing the CIPM MRA in an NMI from an Associate. Promotion and greater acceptance by users of the CIPM MRA was the subject of talks from a number of representatives, and the Directors noted in particular the progress reported by Dr Stephen Carpenter (NIST, USA) on the collaborations he is developing with several US Regulatory Agencies, most notably the Federal Aviation Agency. Other speakers discussed the continuing expansion of the work of the Metre Convention in the areas of chemistry, laboratory medicine and food metrology. Dr Ismael Castelazo, on secondment to the BIPM from CENAM, Mexico, as the Executive Secretary to the JCRB, presented some improvements and simplifications to the RMO processes for CMC approval. These improvements, which have now all been implemented should speed up the inter-regional review procedures.

A recurring theme during the meeting was the relationship between accreditation and metrology at the national and international level. The Director of the BIPM, Professor Andrew Wallard, reported on the joint BIPM/ILAC working group and its efforts to resolve some of these issues at an international level. The working group has already identified the need to review how best to harmonise the assessment of CMCs by RMO technical committees, and the technical assessments needed to accredit NMIs. These issues will be taken up in future meetings.

The Directors also had the opportunity to hear a presentation by Mr Alan Bryden, the Secretary General of ISO. The BIPM and ISO acknowledged the need to work more closely together, particularly on the development of new ISO standards concerning metrology.

Dr Claudine Thomas presented the current state of the KCDB to the Directors. The general response was that the KCDB served the needs of the NMIs very well and that the Directors were pleased with the progress made. In discussion, it emerged that the majority of KCDB users were actually the NMIs rather than industrial or other clients. The Directors felt that the NMIs were, however, well placed to interpret the CMCs and other data in the KCDB. It was proposed that NMIs should develop a facility to help their national users in matters concerning, for example, calibration certificates from other signatories to the CIPM MRA.

Several Directors had also attended the JCRB workshop which took place immediately before their own meeting, and at which the BIPM had presented its own quality system. This presentation had been well received and a number of NMIs asked for copies of BIPM quality documentation.

The most important development at the 13th meeting of the JCRB, held at the BIPM on 29 September 2004, was the approval of a simplified procedure for carrying out the inter-regional review of Calibration and Measurement Capabilities or CMCs.

Before the new procedure was approved, the flow of information between the Chairs of the Technical-Committees (TC) or Working-Groups (WG) was done through the RMO Representatives and the JCRB Executive Secretary. While this method was necessary at the beginning of the MRA in order to monitor and control the process, the JCRB acknowledged that the procedure can now be simplified without compromising its credibility.

In the new procedure, the TC/WG Chairs will be able to post their communications in the JCRB Web page, which will automatically relay them to all interested parties. The JCRB Executive Secretary and the RMO Representatives will be able to monitor every communication

in order to assure compliance with the JCRB rules. It is expected that this new scheme will encourage a more active participation by the TC/WG Chairs, will reduce the review cycle time, and will improve the overall quality of the CMC review process.

  Draft report of the 13th JCRB meeting

Appendix B of the KCDB maintains records of some 590 international (key and supplementary) comparisons conducted by the BIPM, the Consultative Committees (CCs) of the CIPM, and the Regional Metrology Organizations (RMOs).

88 key comparisons correspond to exercises prior to the implementation of the CIPM MRA, and were chosen as "Approved for provisional equivalence". They may be archived as soon as other exercises carried out following the guidelines for key comparisons are available.

Results of key comparisons are interpreted in terms of equivalence and published via the KCDB after formal approval by the appropriate CC. It now displays the results of 160 comparisons.

The results of 19 RMO key comparisons (8 conducted by APMP and 11 by EUROMET) are linked to those of the corresponding CC key comparisons; the full sets of degrees of equivalence are published via the KCDB.

The same type of linkage is also carried out for eight key comparisons of radionuclide activity conducted under the auspices of Section II of the CCRI, and linked to the corresponding ongoing BIPM SIR key comparisons. The latest results of this kind were published for measurements of radionuclide Ir-192.

Some 1500 visits a month are made to Appendix B. This number has remained stable for more than one year. The visitors are mainly people from laboratories that participate in the CIPM MRA.

  Latest KC results published