BIPM BULLE TIN
News from the BIPM
August 2011 www.bipm.org
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
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 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
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
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: email@example.com
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.