News from the BIPM

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News from the BIPM
  August 2011                                                                                                          

                This is the fourth newsletter designed to increase the
                level of communication between the BIPM and its
                                                                                         New States Parties to
                Member States. It supplements the formal reports                         the Metre Convention and
                required under the Metre Convention and highlights
                some key issues and achievements from Session I of                       Associates of the CGPM
                the 100th meeting of the CIPM and the other important
                meetings held in May 2011. My aim is to keep you in
                touch with the BIPM’s work and, as always, I am happy                                           Saudi Arabia became a State Party to
                to respond with further details should you wish.                                                the Metre Convention on 11 February 2011

                Best regards,
                Michael Kühne, Director
                                                                                                                Zambia became an Associate of the CGPM
                                                                                                                on 10 December 2010

                                                                                                                Bosnia and Herzegovina became an
                                                                                                                Associate of the CGPM on 24 May 2011

                                                                                                                Montenegro became an Associate of the
                                                                                                                CGPM on 1 August 2011

                                                                                       There are now 55 States Parties to the Metre Convention
                                                                                       and 34 Associates to the CGPM.

  Session I of the 100th meeting of the CIPM
The 100th meeting of the CIPM will be held in two sessions. Session I took        The main topics of Session I were the BIPM’s draft Programme of Work and
place on 24 May 2011 at the BIPM prior to the meeting of National Metrology       budget for the years 2013 to 2016 and a discussion of alternative funding
Institute (NMI) Directors and the informal meeting of representatives of States   scenarios and the approval of the BIPM financial statements. At the 99th
Parties to the Metre Convention. Session II will be held on 12 to 14 October      meeting of the CIPM, several members had remarked that it was unlikely that
2011, just before the 24th meeting of the CGPM. Session II will include a         all the scientific activities proposed in the Programme of Work could be
celebration of the 100th meeting of the CIPM. Future meetings of the CIPM         funded in view of the difficult economic situation being experienced in a
will be held in May-June of each year instead of October. This change will        number of States. In response to these remarks as well to those made by the
allow the approval of the BIPM financial statements by the CIPM, shortly after    NMI Directors during their meeting in 2010, the BIPM developed four different
the auditors’ report is issued.                                                   funding scenarios. These scenarios ranged from full funding for the proposed
                                                                                  Programme of Work, including the linear accelerator project, through to a
                                                                                  ‘worst case’ scenario which would require a reduction in BIPM core activities.
                                                                                  Details of the scenarios are given later in this newsletter. The scenarios were
                                                                                  thoroughly discussed and examined by the CIPM before being presented at
                                                                                  the meeting of representatives of States Parties to the Metre Convention on
                                                                                  26 to 27 May 2011.
                                                                                  A detailed presentation of the 2010 BIPM financial statements and of the 2010
                                                                                  Pension and Provident Fund financial statements was made to the CIPM. After
                                                                                  the external auditor presented his report to the CIPM on these financial
                                                                                  statements, the CIPM unanimously gave quietus to the Director and the
                                                                                  Financial and Administrative Director of the BIPM for the 2010 BIPM financial
                                                                                  statements. The 2009 BIPM financial statements restated according to IPSAS
                                                                                  on an accrual basis were also approved.                                …/…
The other important topic discussed at Session I of the meeting of          which was also duly circulated to the Member States (Resolution N) for
the CIPM was the governance of the BIPM. This followed the                  consideration during the 24th meeting of the CGPM in October 2011.
submission of three draft resolutions on the governance of the BIPM         Preparations for the Meeting of NMI Directors on 25 May 2011 and the
by the Swiss Confederation (Draft Resolution K); the United Kingdom         informal meeting of representatives of States Parties to the Metre
of Great Britain and Northern Ireland (Draft Resolution L); and the         Convention on 26 to 27 May 2011 were discussed at Session I of the
French Republic (Draft Resolution M). These draft resolutions have          100th meeting of the CIPM.
been duly sent to the States Parties to the Metre Convention. The           Finally, the members of the CIPM decided on the preparations for the
CIPM concluded that a review of the governance and long-term                appointment of the next Director of the BIPM which will begin in the
strategy of the BIPM was needed and, as a result, the CIPM has              near future; this will ensure that a successor is in place when Prof. Michael
prepared an additional draft resolution on governance issues, and on        Kühne retires in March 2014.
the role, mission, objectives and long-term strategy of the BIPM

  Meeting of National Metrology Institute Directors
A meeting of NMI Directors was held at the BIPM on 25 May 2011.             • The unique and invaluable work that the BIPM undertakes on the
The main areas of discussion were: the present situation of the               metrology of pure organic chemicals was highlighted by participants.
redefinition of some units of the SI and on the draft resolution of the     • All participants agreed that the CIPM MRA is a success. The various
CIPM on the possible future revision of the SI; the BIPM’s Programme          points of an addendum to the CIPM MRA were presented and
of Work 2013 to 2016 and the long-term perspective for the BIPM;              discussed. The revised addendum will be sent out for written approval
update of the CIPM MRA; and the present situation on the                      with a deadline for replies.
rapprochement between the BIPM and OIML. The results of the
                                                                            • Discussions involving a potential rapprochement between the BIPM
discussions are summarized as follows:
                                                                              and OIML are ongoing.
• Clarification was provided on the future role of the BIPM and the
  impact on the BIPM Programme of Work of the redefinition of               The three draft resolutions on the governance of the BIPM submitted by
  certain base units of the SI; and the importance of publicizing           the Swiss Confederation (Draft Resolution K); the United Kingdom of
  issues relating to the redefinitions was highlighted. The timetable       Great Britain and Northern Ireland (Draft Resolution L); and the French
  for the redefinitions was discussed, with 2015 suggested as the           Republic (Draft Resolution M) were presented to the NMI Directors. All
  earliest possible date as the situation stands at the moment.             three proposals stem mainly from the strategic issue of the role of the
• The BIPM’s Programme of Work and budget for 2013 to 2016 was              BIPM in relation to the NMIs. The main points of the discussions on the
  described in detail, and four different potential funding scenarios       draft resolutions were:
  were presented (see details of the scenarios later in this newsletter).   • More contact is needed between the Member States, NMI Directors
  In particular, the worst case scenario would represent a major              and the BIPM and the Member States and the NMI Directors would like
  change for the BIPM as it would require the present level of                to be consulted more regularly.
  expenditure to be reduced by 1.4 M Euros with a corresponding
                                                                            • Accountability, decision making and transparency within the CIPM
  reduction in core activities. A clear statement of the ramifications
                                                                              were suggested as areas for improvement.
  and consequences of adopting such a scenario is needed. The
  measures that would need to be implemented under this funding             • The governance of the BIPM should be revised. There is a need to
  scenario would do permanent damage to the BIPM in terms of loss             develop an updated long-term strategy in order to be able to agree
  of expertise.                                                               on the short- and medium-term development of and investments in
                                                                              the BIPM.
• The need for an updated long-term strategy for the BIPM was
  stressed. It is essential that this strategy is prepared before the
  CGPM Meeting in 2015. Development of a ‘World metrology
  strategic plan’ for the entire world-wide metrological community
  was suggested.
       Meeting of representatives of States Parties to
       the Metre Convention to discuss the Programme of Work
       and the corresponding budget for 2013 to 2016
A meeting of representatives of States Parties to the Metre Convention           tending to be around III or IV. Some Member States indicated that they
to discuss the BIPM Programme of Work and the corresponding budget               are willing to support the BIPM with additional voluntary contributions.
for 2013 to 2016 took place at the BIPM from 26 to 27 May 2011. The              Other Member States expressed their view that such contributions
agenda included presentations of the activities of the BIPM scientific           should not incur continuing obligations.
departments and a tour of the BIPM laboratories. As well as discussing the       3. There was unanimous support for a new and stronger strategic
Programme of Work and budget, the four different funding scenarios               direction for BIPM with a clear idea of priorities, developed jointly
with their long-term consequences for the future of the BIPM were                between Member States, NMIs and the CIPM.
                                                                                 4. Some Member States question the current balance between
Scenario I                                                                       coordinating activities and scientific and technical work and whether it
Proposed Programme of Work.                                                      is still appropriate for the future.
Scenario II                                                                      5. A key aspect of the new strategy will be consideration of the
Proposed Programme of Work with the option of financing the linear               appropriate roles of BIPM, Regional Metrology Organizations and NMIs.
accelerator (LINAC) by voluntary contributions.
                                                                                 6. One interesting recommendation was that BIPM should consider
Scenario III                                                                     whether it would be appropriate to charge for some of their services and
Continuation of present activities with an adjustment for inflation to           to share costs for joint activities with other organizations.
allow the current level of effort to be maintained.
                                                                                 7. Discussions on the modernization of governance structures should go
Scenario IV                                                                      in parallel with strategic developments.
No increase in contributions from Member States, no inflationary increase
                                                                                 8. There is a strong feeling that changes should not wait until the next
and consequently a reduction or discontinuation of activities.
                                                                                 scheduled CGPM in 2015.

During a closed session (without the presence of any CIPM members who
                                                                                 The three government-initiated draft resolutions related to the
were not part of government delegations and without any BIPM staff
                                                                                 governance of the BIPM, that were presented and discussed at the
members) the representatives discussed the BIPM’s Programme of Work
                                                                                 meeting, provided valuable feedback to the CIPM over concerns
for 2013-2016, the funding scenarios and other issues. The results of the
                                                                                 expressed by a number of delegations. With the encouragement of the
closed session were summarized by the representatives of the States as
                                                                                 representatives of States Parties to the Metre Convention, the CIPM was
                                                                                 prompted to initiate an additional draft resolution on governance issues
1. All States strongly support and appreciate the Metre Convention and           (Resolution N) for consideration during the 24th meeting of the CGPM in
the work of the BIPM, noting that it is moving forward, for example with         October 2011. Overall the meeting proved to be very successful and was
the development of the CIPM MRA.                                                 seen as a valuable communication forum. It was recommended that it
2. The range of views on funding scenarios stretched from support for            should be held on a regular basis, perhaps annually.
Scenario I and II to a desire for a less than Scenario IV, with the majority

      The CIPM MRA                                                        David Burns elected as a Fellow
                                                                          of the Institute of Physics
   So far in 2011, the National Metrology Institutes
   (NMIs) of seven States have signed the CIPM MRA:
   Zimbabwe on 14 January 2011; Zambia on 3 February                   Dr David T. Burns, Principal Physicist in the BIPM’s Ionizing Radiation Department,
   2011; Mauritius on 9 March 2011; Bangladesh on 25                   has been elected a Fellow of the Institute of Physics in the UK, in recognition of his
   March 2011; Saudi Arabia on 25 May 2011; Bosnia                     personal contribution to the advancement of physics. The BIPM is proud to
   and Herzegovina on 15 June 2011 and Pakistan on 6                   announce this honour in acknowledgment of his scientific research, publications,
   July 2011.                                                          international standing and supervision of the BIPM international dosimetry
   At the time of this newsletter, the CIPM MRA has                    standards programme.
   been signed by the representatives of 86 institutes –
   from 50 Member States, 33 Associates of the CGPM,
   and 3 international organizations – and covers a
   further 137 institutes designated by the signatory
                                                                                   Progressing from a 1-axis to a 3-axis interferometer has improved the
  The BIPM watt balance                                                            voltage to velocity signal to noise ratio by a factor of 10 and the relative
                                                                                   uncertainty on h has improved.
                                                                                  • An original procedure has been developed and tested to ensure that the
                                                                                    electric force exerted on the watt balance coil is parallel to the
The watt balance is one of the BIPM’s most important projects, which was
                                                                                    gravitational force exerted on the test mass. During this procedure the
given highest priority in the Programme of Work 2009 to 2012. This
                                                                                    electric plane of the coil is aligned perpendicular to the local gravity
project, together with the ensemble of mass standards, is essential for the
                                                                                    vector, and the magnetic field is aligned to be radial to the coil. The
BIPM’s future responsibility for mass metrology after the redefinition of
                                                                                    alignment procedure has been tested with a trial coil which has the same
the kilogram.
                                                                                    characteristics as the final watt balance coil (1200 turns, 250 mm
The distinguishing characteristic of the BIPM watt balance with respect to          diameter). The results were successful, proving that the electric force can
all other watt balances world-wide is that it carries out both measurement          be made parallel to the gravitational force to within 50 µrad. This accuracy
phases (weighing and moving experiments) simultaneously. The great                  is enough to allow h to be measured at the 10–8 level. This alignment will
advantage of this simultaneous measurement is to guarantee that the                 be carried out with the real watt balance coil in the near future.
geometric properties of the coil, the coil orientation and the magnetic           • A new laboratory with two large concrete foundations, one for the watt
field, acting in both phases are strictly the same. The disadvantage is the         balance, the other for a gravimeter, is now ready. The vibration level on
appearance of an undesirable voltage drop in the coil, which is a result of         these foundations is considerably lower than at the present location,
the current flow and the non-zero resistance of the coil. This undesirable          which will reduce the noise level of the measurements. The move to the
voltage drop needs to be separated from the induced voltage with an                 new laboratory will provide the opportunity to install the watt balance in
uncertainty of 1 part in 108. Such high accuracy is difficult to achieve at         a vacuum enclosure which is now available. With all these improvements,
room temperature due to the resistance changes in the coil as a                     an uncertainty of the order of 1 part in 106 is expected to be reached in
consequence of its temperature coefficient.                                         early 2012.
A feasibility study was carried out to investigate the behaviour of a
                                                                                  • A new closed magnet circuit will be soon integrated into the experiment.
superconducting coil, with support from NIST, and to explore some of the
                                                                                    The design and fabrication of the two samarium-cobalt (Sm2Co17)
engineering difficulties of developing a cryogenic watt balance.
                                                                                    magnets has been completed. The circuit design includes two discs of
Construction of a small-scale superconducting moving coil system has
                                                                                    Sm2Co17 magnets, magnetized in opposite directions, as the flux source.
                                                                                    The yoke is made of FeNi which has been selected for its high magnetic
In early 2010 the BIPM watt balance measured, for the first time, the Planck        permeability and its mechanical stability at cryogenic temperatures. The
constant h in air at atmospheric pressure. It demonstrated at a level of            mean diameter of the circular air gap is 250 mm and the width is 13 mm.
parts in 105, that it is possible to realize the two-phase principle originally     The magnetic field will have radial symmetry and a magnetic flux density
proposed by B.P. Kibble in 1975 using only one phase by measuring all               of about 0.5 T. Construction of the housing for the magnets is under way.
quantities at once. The reproducibility of the Planck constant measurement,         One of the properties of the system is that the magnets and the air gap
at the present time, is 5.6 × 10–6. The relative difference between this            are completely screened by a high permeability iron yoke. This should
result and the recommended CODATA 2006 value is – 4.8 × 10–6. The total             considerably reduce the level of external electromagnetic perturbations
relative uncertainty of h is currently 4.9 × 10–5. With this result, the BIPM       detected by the coil. The symmetry of the circuit with respect to the
joined NIST, NPL and METAS as the only bodies with published results of             horizontal plane helps to improve the uniformity of the flux density in the
watt balance experiments. Picard A., Bradley M.P., Fang H., Kiss A., de             air gap. The details of the mechanical design and the machining
Mirandes E., Parker B., Solve S., Stock M., The BIPM Watt Balance:                  techniques required to realize the necessary small tolerances are under
Improvements and Developments, IEEE Trans. Inst. Meas., 2011, 60(7),                investigation. A simpler magnet is currently installed in the experiment.
2378–2386                                                                         • Work has started on a dedicated Josephson voltage standard for the
Significant progress has been made on the watt balance since the first              voltage measurements.
measurements of h were made:                                                      Work will continue on the present room-temperature instrument until it
• Measurement of the vertical coil movement and the related velocity has          has reached its uncertainty limits. The target is to reach an uncertainty
  improved following the installation of a 3-axis heterodyne interferometer.      below 5 parts in 108 by the end of 2014.

                                                                                                          Dr Takashi Usuda, a visiting scientist at the BIPM
                        The NEN (the Netherlands Standardization Institute)                               seconded by the NMIJ, Japan, was awarded the
                        and ISO/TC 158 “Analysis of gases” organized the 6th                              prestigious Ichimura Prize in Technology on 28
                        International Gas Analysis Symposium & Exhibition                                 April 2011 by the New Technology Development
                        (GAS2011) from 9 to 11 February 2011. Over 220                                    Foundation, Japan, for his contribution to
                                                                                                                                                                   Graphic Design:

                        people attended the symposium which included 60                                   improvement of the National Metrology Standard
                        lectures and 25 exhibitors. The GAS2011 best lecture                              of Vibration Measurement. The award was in
                        award was won by Dr Joële Viallon from the BIPM’s          recognition of his work to develop a laser interferometer for vibration
Chemistry Department, with her lecture entitled “Dynamic generation of             acceleration calibration. The laser interferometer enables high resolution
formaldehyde standards by permeation tubes: performance evaluation                 and robust characteristics against vibration noise. Dr Usuda also
using FTIR and cavity ring-down spectroscopy techniques”, given during the         established the national calibration programme for vibration acceleration
session “Metrology, Accreditation & Chemometrics”. The work described              in Japan. His achievements improved the Japanese metrology standard
validation studies being performed at the BIPM in preparation for the key          of vibration measurement and ensured the traceability of vibration
comparison CCQM-K90 on formaldehyde in nitrogen.                                   measurements in industry to the national standard.