The BIPM key comparison database Newsletter - No 13 - June 2010
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Dear Reader,

Welcome to the 13th KCDB Newsletter.

In this issue we highlight some updates related to the CIPM MRA, the JCRB, the content of the KCDB, and various events and news concerning the BIPM. General information on future meetings is provided on the BIPM main website: calendar of meetings held at the BIPM, and other conferences, workshops and general assemblies.
As usual, we begin with a novel success story related to the use of the CIPM MRA.
We wish you a pleasant time surfing our KCDB Newsletter No 13,
The BIPM KCDB Office

To improve future editions of the KCDB Newsletter, please send us feedback to so that we may meet your specific interests and concerns.

The complete series of KCDB Newsletters is available here.

The success story of the KCDB Newsletter No 13:

  "Benefits of the CIPM MRA for the National Physical Laboratory of India" by Dr. A.K. Bandyopadhyay, Head, Physico-Mechanical Standards, National Physical Laboratory, New Delhi - India.

Climate change - WMO signed the CIPM MRA!

The "WMO-BIPM Workshop on Measurement Challenges for Global Observation Systems for Climate Change Monitoring: Traceability, Stability and Uncertainty" was held from 30 March to 1 April 2010, at the WMO headquarters in Geneva, Switzerland, under the chairmanship of Prof. Andrew Wallard (BIPM) and Dr Wenjian Zhang (WMO).

At the occasion of the Workshop, the World Meteorological Organization (WMO) joined the CIPM MRA. The signing ceremony took place on 1 April 2010, when Michel Jarraud, Secretary General of the WMO, signed the Arrangement on behalf of the WMO.


WMO-BIPM Workshop on Measurement Challenges for Global Observation Systems for Climate Change Monitoring: Traceability, Stability and Uncertainty
30 March-1 April 2010

Co-chairs: Prof. A. Wallard (BIPM), Dr W. Zhang (WMO)
Co-chairs of the Steering Committee: Dr B. Calpini (WMO), Dr R. Wielgosz (BIPM)
Co-coordinators of the Workshop: Dr O. Baddour (WMO), Dr P. Espina (NIST)



Workshop Objectives

  A.  Identify key measurement issues in climate science, Numerical Weather Prediction model (NWP) and Earth observation where there is a requirement for improved underpinning metrology.
  B.  Foster closer links and develop dialogue between the metrology and the Earth observation systems communities.
  C.  Drive agenda setting and road mapping within National Metrology Institutes (NMIs) and ensure that measurement science is developed to meet the needs of climate science, NWP and Earth observation community needs.
  D.  Inform the Earth observation systems community about the capabilities and plans of the NMIs.

Prof. A. Wallard's words on the Workshop
Prof. Wallard's address to the CCT plenary meeting on 6 May 2010:

"We held a joint Workshop with the World Meteorological Organization on the broad subject of Metrology and Climate Change, and how satellite-based, ground-based and other monitoring techniques can be improved by the adoption of best-practice metrology.
It was a two-day Workshop in Geneva with a fascinating series of presentations and a great deal of commitment by our colleagues in the meteorological community to take much greater advantage of the expertise that is in National Metrology Institutes.
For us, it was a major step forward because although there have been a lot of working-level contacts in a variety of different disciplines between the metrologists and parts of the observation networks - the Global Atmospheric Watch and GEOS networks - it really became a major commitment by the WMO at the most senior level.
For those of you who would like to look at it in a little bit more detail, all the presentations that were given at the Workshop can be found on the open BIPM website. Our aim is to produce a report by end of June that will contain all the recommendations and the conclusions that we drew from the Workshop, and it will probably be a joint BIPM/WMO document. It will be circulated very widely, including to governments, intergovernmental organizations, NMIs Directors, the international panel on climate change, the UNCCC that deals with this, and to anybody else we can think of, because I think it is a major step forward to have the commitment of two of the world intergovernmental organizations, tackling the metrology and measurements issues in what, I am sure we all agree, is one of the most major challenges of the world at the moment.
This is a hugely important and active area with demands from the practical observation community, satellite people, calibration, specifications of what is needed in terms of monitoring global greenhouse gases, in terms of concentrations, in terms of temperature measurements in sea-based measurements and a variety of other things. So there is a wide range of subjects within this particular topic.
From our point of view, we will carry the work forward with as much energy as we can. One of the things we want to do is to set up clear liaison links between the relevant Consultative Committees and the WMO, so that the interactions can be realized in a positive and active way. We will certainly also be setting up a joint group with the WMO to monitor the actions and make sure things do happen.

The World Meteorological Organization (WMO) signed the CIPM MRA
on 1 April 2010

From left to right: Dr L. Barrie (WMO), Prof. A. Wallard (BIPM),
Dr M. Jarraud (WMO), Prof. E. Göbel (CIPM), and Dr W. Zhang (WMO)

The WMO has designated three laboratories to represent it in activities organized within the CIPM MRA:
  1.  World Radiation Centre (PMOD/WRC, Davos, Switzerland), for solar irradiance;
  2.  World Calibration Centre (WCC-Empa, Dübendorf, Switzerland), for surface ozone; and
  3.  National Oceanic and Atmospheric Administration Earth System Research Laboratory (NOAA/ESRL, Boulder, Colorado, USA), for carbon dioxide, methane, nitrous oxide and carbon monoxide concentrations.

(Information collected by Dr C. Thomas, BIPM)

BIPM Membership and Associates of the CGPM

Since the issue of the KCDB Newsletter No 12, and in addition to the WMO signature (see above), the BIPM has registered one further signature of the CIPM MRA:
  -  Mr. Adu Darkwa, then Executive Director of the Ghana Standards Board (GSB), Republic of Ghana, signed the CIPM MRA on 24 February 2010. The Republic of Ghana had become an Associate of the CGPM on 17 September 2009.

As of 26 May 2010, the CIPM MRA has been signed by representatives of 78 institutes from 48 Member States, 27 Associates of the CGPM, and three international organizations, and covers a further 128 institutes designated by the signatory bodies as holders of specific national standards. Click here to access the full list of participants in the CIPM MRA.

The Republic of Kenya, previously Associate of the CGPM became a Member State of the BIPM on 1st January 2010, and the People's Republic of Bangladesh became an Associate of the CGPM on 29 March 2010. This brings the current number of Member States of the BIPM to 54, and of Associates to 28.

See the full list of Member States and Associates

(Information taken from the BIPM website)

World Metrology Day - 20 May 2010


Measurements in Science and Technology

A bridge to innovation

Press release

On World Metrology Day more than eighty States celebrate the impact of measurement on our daily life, no part of which is untouched by this essential, and largely hidden, aspect of modern society. Previous themes have included topics such as measurements in sport, the environment, medicine, and trade. The 2010 theme concentrates on how measurement influences science and stimulates innovation. As the world strives to move on from its recent financial problems, and as Governments work to regenerate economies, we shall find that science and technology are the engines of economic growth and prosperity. These, in turn, rely on being able to measure correctly and to refer measurements to the same international reference standards. A world without accurate measurement is a world where science, technology, trade and society can't communicate and where error and uncertainty would reign supreme… For more, click here.

Message of the Director of the BIPM

(An initiative conducted by Mr L. Mussio)

The 2010 WMD poster

Feedback from the 24th JCRB

The 24th meeting of the JCRB took place at the BIPM in Sèvres on 16-17 March 2010.

CIPM MRA documents and policies

Four documents were discussed in the meeting:
  - CIPM MRA-D-05 (Interlaboratory Comparisons in the CIPM MRA);
  - CIPM MRA-D-04 (Calibration and Measurement Capabilities in the context of the CIPM MRA);
  - CIPM MRA-G-02 (JCRB guidelines for the monitoring and reporting of the operation of Quality Systems by RMOs); and
  - CIPM MRA-D-06 (Approval of CIPM MRA policy documents).
The discussion on these documents will continue by correspondence and will be included in the agenda of the next meeting.

Status of CMCs temporarily removed from KCDB

It was resolved that after five years, CMCs in the "temporarily removed" status (greyed-out CMCs) cannot be reinstated without a full review and should be deleted from the KCDB. A procedure to enforce this resolution will be discussed at the next meeting.

Quality Systems

Although the BIPM is not a signatory of the CIPM MRA, and following the decision to publish BIPM measurement capabilities on the BIPM website, it was decided that the BIPM will annually include in the reports to the JCRB, relevant information about its Quality System. It was also decided that every two years, in conjunction with the presentations of the RMOs Quality Working Groups, the BIPM will make a presentation of its Quality System.

The JCRB decided to recommend to the CIPM the adoption of the following policy: "The initial and periodic presentations of the QS of Designated Institutes (DI) to the corresponding QS review panel of the RMOs, must be made directly by the responsible person of the DI and not through its NMI. In the same sense, the annual QS reports must also be prepared and submitted directly by the DI."

Participants in the 24th meeting of the JCRB
BIPM, 16 March 2010

On-site peer reviews

Noting that the RMOs are moving to a common position in which on-site peer reviews are considered the best practice to assure the capability of the CIPM MRA participants, the RMOs have decided to have an internal discussion about making such on-site peer reviews mandatory: the results of these discussion will be reported at the next meeting of the JCRB.


The JCRB recommends that the BIPM continues working in the ILAC Accreditation Issues Committee (AIC) in relation to the document "Accreditation of NMIs".

The next meeting of the JCRB will be hosted by AFRIMETS on 21 and 22 September 2010, and organized by NIS, Egypt, in conjunction with the AFRIMETS General Assembly.

(Reported by Mr. L. Mussio, JCRB Executive Secretary,, JCRB website)

 CIPM MRA documents

Feedback from the 2010 Directors' meeting

This year the Directors' meeting took place at the BIPM on 2-3 June 2010. This annual meeting provided the opportunity for the Directors of the National Metrology Institutes and the Designated Institutes to discuss current issues with the BIPM. These ranged from the outcomes of the various workshops held during the year, the strengthening relationship between the BIPM and organizations such as the WMO and ILAC, to the progress on the redefinition of the SI. Particular focus this year was also given to the draft 2013-2016 BIPM Programme of Work, which will be presented to the CIPM in October, and eventually to the CGPM next year. As expected the draft Programme of Work stimulated a lively debate, and the feedback will help the BIPM to take the draft to the next stage.

The meeting also provided an opportunity for high profile speakers to present on important topics of the moment. Five presentations were given this year, addressing:
  - WMO Climate System Monitoring and the Role of WMO-BIPM Joint Activities, by Mr. Omar Baddour, WMO;
  - Measurement Aspects of Carbon Trading - Carbon Economy, by Prof. João Alziro Herz da Jornada, INMETRO, Brazil;
  - Biology and Nanotechnology: Risk Management, Standards and Regulation, by Dr Richard Moore, Institute of Nanotechnology, UK;
  - Economic Impact of Metrology: a Review of Recent Studies, by Mr Robert Gunn, National Measurement Office, UK; and
  - Stem Cell Biology and Regenerative Medicine, by Prof. Renée A. Reijo Pera, Stanford University School of Medicine, USA.
The presentations were well received and stimulated a number of questions and discussions, which continued in many cases long after the meeting was formally closed!

(Reported by Dr A. Henson, International Liaison Officer, BIPM)

BIPM Workshop on Metrology at the Nanoscale

Held at the BIPM on 18-19 February 2010
Chairman: Dr Alan Steele, NRC
Scientific Secretary: Dr Joële Viallon, BIPM


Acknowledging the importance of measurement science and metrology in emerging areas of technology, the BIPM organized and hosted a Workshop on Metrology at the Nanoscale, bringing together scientists from the NMIs and industry with experts from the regulatory and standards development community. The two day Workshop, held on 18-19 February 2010 and involving more than 100 participants, approached the very broad topic of nanotechnology with thematic lectures and round-table discussions in eight topical areas:
  - Toxicological testing;
  - Nanobiology;
  - Aerosols;
  - Microscopy;
  - Surface analysis;
  - Thin films and coatings;
  - Mechanical metrology; and
  - Electrical and magnetic applications and measurements.

The program was very lively, and the presentations were uniformly excellent, allowing the attendees to address the focal question of the meeting:

"What activities are required to establish an effective international
infrastructure for metrology at the nanoscale

The full report, which will be released this summer, includes a comprehensive summary of the discussions on this question, including the drivers to work on the topic, technical issues and barriers to progress, status and needs for traceability to the SI, as well as the anticipated use and need for reference materials and documentary standards. Briefly, however, it can be said that the principal drivers for international involvement are in environment, health and safety, in supporting and defining an appropriate regulatory framework, in encouraging and fostering industrial and therefore economic advantage. While the element of curiosity to explore new areas was an overarching theme, one principal barrier to progress was the long lead time required to develop research into innovation. Although there is a varied level of maturity in metrology and standardization, it was acknowledged that there is growing awareness and a high level of anticipation for results.

The current and potential applications of nanotechnology are vast, and there is a great deal of work required to advance the state of the science to ensure the safe and responsible introduction of these new technologies. Perhaps the most rewarding element of the Workshop was the opportunity to meet and establish connections outside of our normal communities: this sentiment was echoed with equal enthusiasm by participants from the world of metrology, by the industrial delegations, and by the attendees from international standards and policy development. We were presented with a very broad spectrum of measurement techniques and instrumentation, of new and very challenging measurands, and of the need to act across traditional organization- and discipline-based boundaries to ensure that these pressing needs are met.

"I was very pleased with the level of engagement over the two hectic days, and with the superlative efforts of the Session Chairs and Discussion Hosts who each gave a summary of the work done in the breakout sessions. The BIPM was an ideal venue for such a cross-cutting Workshop, and I know that I speak for everyone who participated when I offer my sincere thanks for the chance to participate and express my desire to attend another productive meeting at some point in the future!"

(By Dr A.G. Steele, NRC, Canada, Chairman of the Workshop)

KCDB: key and supplementary comparisons

The key and supplementary comparisons database now covers 693 key comparisons (82 from the BIPM, 337 from the CCs, 1 from AFRIMETS, 95 from APMP, 29 from COOMET, 111 from EURAMET, and 38 from SIM) and 244 supplementary comparisons.

Number of key comparisons and of supplementary comparisons registered in the KCDB: evolution since September 2003

Number of new comparisons registered in the KCDB over the one-year period ending at the date indicated on the x-axis

The rate of registration of supplementary comparisons is still increasing and has now reached the one observed for key comparisons, with about 35 new exercises declared to the KCDB Office over one year.

Updated graphs illustrating the participation in key and supplementary comparisons were made available from the Statistics page of the KCDB on 18 May 2010.

On 24 May 2010, among the 693 key comparisons that were registered:
  - 88 corresponded to exercises prior to the implementation of the CIPM MRA (they were "Approved for provisional equivalence");
  - 73 of the 82 ongoing BIPM key comparisons had results published in the KCDB; these are regularly extended when new data become available; and
  - another 310 CC and RMO key comparisons had their final reports approved and posted in the KCDB website, and corresponding tables of numbers and graphs entered in the database.
All together, the KCDB currently displays a total of about 1450 graphs of equivalence, including more than 150 new graphs of equivalence published over the last six months.

The results of some 119 RMO key comparisons are published in the KCDB. Linkage is also computed for bilateral key comparisons subsequent to full-scale CC key comparisons; their results are added on the appropriate graphs of equivalence. The final reports (or appropriate references) of more than half of the supplementary comparisons registered in the KCDB are also posted in the KCDB.
Note that final reports of key and supplementary comparisons posted in the KCDB are also generally published in the Metrologia Technical Supplement.

 Latest KC results published

KCDB: Calibration and Measurement Capabilities (CMCs)

As mid-May 2010, about 23 000 CMCs were published in the KCDB. This represents an additional 1 800 CMCs compared to mid-May 2009. Indeed, over the last year a large number of newly approved sets of CMCs have been published.

One also observes a continuous movement linked to approval of Quality Systems: temporary removal (so-called "greying-out") of CMCs not covered by an approved QS, and re-instatement of CMCs once the QS covering them is approved.

As of 18 May 2009, 451 CMCs are greyed-out from the KCDB. This number has remained constant since the 21st JCRB meeting when an action was taken to clear up the long-standing issue of the situation of the hundreds of CMCs that were greyed-out from the KCDB in July 2005 (just after the 15th JCRB meeting), in particular through definitive deletion of a number of CMCs.

Up-to-date details on the number of CMCs currently published in the KCDB, per country and per metrology area, are available from the Statistics page of the KCDB.

In addition, a record of the history of CMC publications (including greying-out and re-instatement following QS approval) is kept in the form of an EXCEL file, which is made available in real-time from the restricted-access part of the JCRB CMCs website. Following a request of the JCRB at its 24th meeting, the dates of greying-out of CMCs are now included in this file. This makes it possible to spot those CMCs that have been greyed-out for more than five years, and for which further examination may be needed.

 Latest CMCs published

Visits to the KCDB website

As reported previously, new software analysing the connections to the KCDB website was implemented in January 2009.

During 2009, more than 90 000 visitors opened a total of about 821 000 KCDB web pages. The number of monthly visits varied between 5 600 and 10 100, and the number of pages opened each month between 48 800 and 117 500. These counts, however, do not include the additional fraction of visitors arriving at the KCDB via our free-text search engine installed on the main BIPM website.

All pages are equally visited, including the News page, the Statistics page, and the Newsletters; and PDF files of comparison reports and of CMC lists are regularly downloaded.

Visitors come from all over the world, and reach the KCDB website from:
  - bookmarking, direct URL address typing or using links given in e-mails for about 70 % of them,
  - Internet search engines (Google, Yahoo, etc.) for about 5 % of them, and
  - links proposed in other websites (especially NMI websites) for the remaining 25 %.
It is difficult to identify our visitors apart from the National Metrology Institutes which obviously constitute a part of the audience; but the numbers indicate that our site also attracts other communities, including regulators, accreditors, and commercial and industrial companies.

Modification of the KCDB website

A number of changes were brought to the KCDB web programming in February 2010. These include re-structuring the box entitled "Related links" provided on the left of the KCDB website, and also the introduction of a new web page including answers to frequently asked questions (FAQs).

The box "Related links" is placed in all pages of the KCDB website. Among others, it gives access to the KCDB Statistics page and to the CIPM MRA website, which contains useful procedural documents.

The FAQs page currently gives answers about ten different themes spotted in the mails received from the KCDB users. Others to come!

Links to a number of KCDB web pages and other related web sites as proposed from the KCDB website

(KCDB Report by Dr C. Thomas, BIPM KCDB Coordinator)

50th anniversary of the SI: the International System of Units

The year 2010 is the 50th anniversary of the adoption of the name "International System of Units", and the symbol "SI" (taken from the French words Système international d'unités), by the 11th General Conference on Weights and Measures (CGPM, Conférence Générale des Poids et Mesures) at its meeting in 1960. This 11th meeting of the General Conference was thus the formal beginning of the SI. The success of the SI in providing internationally agreed standards for the world of science, engineering and technology is an occasion to be celebrated.

The BIPM was originally established in 1875 by the Metre Convention to ensure world-wide unification of measurements. At its 1st meeting, in 1889, the General Conference decided definitions of the metre and the kilogram in terms of prototype artefacts. Definitions of the electrical units based on the ampere were added at the 9th meeting of the General Conference, in 1948, in agreement with the IEC. At the same conference the candela was adopted as the name of the unit of luminous intensity in place of the older "new candle". The definition of the kelvin was added at the 10th meeting of the General Conference, in 1954, and the formal definition of the second was added by the CIPM in 1956. Finally the 11th meeting of the General Conference in 1960 laid the foundation for the complete system of units, built upon the six base units used at that time and including multiple and sub-multiple prefixes, and adopted the name International System of Units by which the entire system is known today. The definition of the mole for the quantity amount of substance, the seventh base unit, was added at the 14th meeting of the General Conference in 1971.

There have been many developments to the system during the 50 years from 1960 to 2010. The definitions of many of the base units have been revised to meet new developments in the experimental basis of metrology, and to ensure the coherence of the entire system. These changes have been faithfully recorded in successive editions of the SI Brochure, prepared by the Consultative Committee for Units (CCU) and published by the BIPM at irregular intervals.

The Brochure has grown from the 36 pages of the original first edition to the 200 pages of the latest 8th edition published in 2006. The 8th edition is also accompanied for the first time by the four-A4 page Concise Summary of the SI. These publications are available free on the BIPM website, and are now accepted around the world as the reference standard for all quantitative measurements.

The SI has now reached maturity as the ultimate international reference for all standards of measurement. But it is a living system, forever being revised and improved in a variety of ways to recognize our developing abilities in making measurements. At present there are active plans to revise the definitions of four of the seven base units - the kilogram, ampere, kelvin and the mole - as we strive to achieve a more uniform system in which the definition of all units are referenced to the fundamental constants of nature.

Happy 50th birthday to the SI!
May it continue to prosper in the hands of the metrologists of the world.

(by Prof. I.M. Mills, President of the CCU)

 The 8th edition of the SI Brochure

The BIPM/NMIA calculable capacitor

Establishing a calculable capacitor at BIPM:
a collaboration between BIPM and NMIA

Progress report - May 2010

A photograph of the calculable capacitor main cell during construction, showing one electrode bar installed and three sapphire ball mounts ready to receive the remaining bars.

The capacitor main electrodes (solid stainless steel bars 0.5 m long and 50 mm in diameter) have been manufactured at the National Measurement Institute of Australia (NMIA) using a carefully monitored hand lapping process. The finished bars show deviations from a perfect cylinder of less than 100 nm along the entire working length of 400 mm. This remarkable precision of manufacturing will allow an absolute capacitance standard with a relative uncertainty of a few parts in 109 to be implemented (via the Thompson Lampard theorem of electrostatics).

The complete instrument includes many other precision mechanical components and an interferometer is needed to measure the displacement of a moveable guard electrode. It is expected to be fully assembled later this year, ready to start serious measurements. The measurement task will be to relate the capacitance implemented by the new instrument (around 0.2 pF) to the standards maintained by the BIPM in terms of the quantum Hall effect (a quantized resistance of around 13 kiloohms). The result can be interpreted in two ways: as a direct SI measurement of the von Klitzing constant, RK, or as a purely electrical determination of the fine structure constant, alpha .

Regardless of the interpretation, the aim is the same: to contribute new experimental data on the fundamental constants as part of the effort to ensure any future changes to the SI are based on solid metrology. The completed instrument should also serve as a practical capacitance standard for the BIPM's calibration services and comparisons work.

(Photo and text: Mr N. Fletcher, Electricity Department, BIPM)

Advance notice

"21st Century Innovations in Metrology"
To be held on 25 - 29 July 2010 in Providence, Rhode Island, United States
NCSLI Workshop and Symposium - 2010

"The new SI: units of measurement and fundamental constants"

A Royal Society Discussion Meeting
to be held on 24 - 25 January 2011 in London, United Kingdom
Organized by Dr T.J. Quinn, Prof. I.M. Mills and Dr P. Gill

The kilogram is still defined as the mass of a Pt-Ir cylinder kept in a vault in Sèvres. It is now planned to redefine the kilogram by fixing the numerical value of the Planck constant h, so that the definition will no longer be based on an artefact. Similarly the ampere, kelvin and mole may be redefined in terms of fixed numerical values for e, k and NA, so that all these SI units are linked to fundamental constants of nature. A future redefinition of the second in terms of an optical rather than a microwave transition is also being considered.

The Royal Society

"Added value through better measurement"
To be held on 3 - 6 October 2011 in Paris, France
Collège Français de Métrologie

 Calendar of meetings held at the BIPM

 Other conferences, workshops and general assemblies