INFOSIM

INDICE

CONTENTS

EditorialHéctor Nava Jaimes....................................................................………...……5

Nuevo Presidente del SIM / New SIM President………………..……….……..7

Report of the President (November 2005 - September 2006)Dianne Lalla-Rodrígues…………………………………………………….……...7

Watt balances and the future of the kilogramMichael Stock…………………………………………………………................... 9

NIST-Promoting innovation, competitiveness and facilitating tradeHratch G. Semerjian.........…………………………………………………….….14

NMIJ strategies to face the increasing needs in metrologyMitsuru Tanaka ..........………………………………………………….…..….....20

Interlaboratory mass comparison between laboratories belongingto SIM-sub-region coordinated by CENAMJorge Nava, Luis O. Becerra, Tweedsmuir Mitchell, Mairy Sanz,Olman Ramos, Sandra Rodríguez, Gerson Vallejos, Marco Bautista,Francisco García, Fernando Leyton, Aldo Quiroga, Juan G. Rodríguez,Rubén Ramírez, Arnoldo Florencio................................................................25

NOTI-SIM………………………………………………………………………….33

4

5

EDITORIAL EDITORIAL

El Sistema Interamericano de Metrología, como un

organismo creado para promover la colaboración

internacional y regional en metrología, ha

establecido el boletín INFOSIM como uno de los

medios destinados a intercambiar o transferir

conocimientos técnicos en beneficio de las

economías asociadas.

Esta edición del INFOSIM incluye noticias

relevantes dentro del marco de la metrología de las

Américas, entre las cuales destacan el informe de la

Presidenta del SIM en el periodo noviembre de 2005

a septiembre de 2006 y la elección del Prof.

Humberto S. Brandi como nuevo Presidente.

Adicionalmente, reproduce, en el idioma en que

fueron recibidos, algunos trabajos expuestos en el

SIMPOSIO de METROLOGÍA 2006, celebrado

recientemente en la ciudad de Querétaro, México.

Dos de estos trabajos se abocan a las relaciones

entre los INM y la sociedad, otro señala el rumbo de

la metrología hacia el uso de constantes

fundamentales, y uno más sobre una comparación

en masa entre algunos INM, como un indicio del

estado en que se encuentra la metrología en el SIM.

Finalmente, se ha incorporado la sección NOTI-SIM

para difundir los diversos acontecimientos en

nuestra comunidad. En esta ocasión se comenta

sobre la XII Asamblea General del SIM en Río de

Janeiro, Brasil, y se informa sobre algunas

actividades sobresalientes.

Esperamos que el contenido de este boletín propicie

la reflexión sobre el estado en que se encuentra la

metrología, hacia dónde se dirige; cuáles son

nuestras necesidades y cuáles nuestras

oportunidades para mejorar las economías de

nuestros países, en el ámbito de lo que podemos

hacer: las buenas mediciones.

The Interamerican Metrology System, as an

organization devoted to promote international and

regional cooperation in metrology, has established

INFOSIM as a means to exchange and transfer

technical knowledge to benefit the associated

economies.

This edition of INFOSIM includes, as highlights

within the framework of metrology in the Americas,

the President's Report for the period November

2005 - September 2006, and the election of Prof.

Humberto S. Brandi as the new SIM President.

Furthermore, it reproduces some of the papers

presented in the SIMPOSIO de METROLOGÍA

2006, recently held in Querétaro, México. Two of

these papers deal with the relationship between

metrology and society, one more addresses the

trend towards the use of fundamental constants,

and another provides clues on the state of

metrology in some SIM NMIs, through a mass

comparison.

Finally, it introduces the NOTI-SIM section, aimed at

divulging the activities in the SIM community. It

contains comments on the XII SIM General

Assembly General held in Río de Janeiro, Brazil, as

well as brief reports on other important activities.

Our hope is that the contents of this bulletin leads to

a reflection on the present state of metrology, its

trends, our needs and our opportunities to improve

the economies of our countries. All this in the context

of our core business: good measurements.

Héctor Nava JaimesCENAM, México, Director General / Director General

46

7

Nuevo Presidente del SIM

Nos congratulamos por la elección del profesor Humberto Brandi -

Director de Metrología del INMETRO- como nuevo Presidente del SIM

para el periodo Septiembre 2006- Septiembre 2008, y le deseamos

éxito en su nueva responsabilidad.

New SIM President

The SIM community welcomes the election of Professor Humberto

Brandi - Director of Metrology, INMETRO- as the new SIM President for

September 2006 - September 2008. We wish him the major of the

successes in this responsibility.

Report of the President(November 2005-September 2006)

Welcome and Opening Remarks

I wish to warmly welcome all colleagues in Metrology to this year's 12th SIM

Annual General Assembly. I especially wish to welcome our colleagues from the

other RMO's and from the other International Metrology Organisations. I would

like to thank you all for taking time our of your busy schedules to be present with

us and we anxiously await your reports, since it is an opportunity for the wider

SIM Community to be made aware of the work that you are doing in metrology in

your various regional metrology organisations .

SIM Project 2002-2004 - Metrology for the Americas

The activities of the above-captioned Project were completed on schedule;

however a comprehensive review/evaluation of the project was requested by

SEDI/FEMCIDI.

The goal of this evaluation was to study and provide results on evaluation

findings relating to five dimensions of the Project: (i) relevance; (ii) efficiency

(relation between resources used and activities executed); (iii) effectiveness

(degree to which expected results have been attained); (iv) best practices and

lessons learned; and (v) sustainability. The Project evaluator was Mr Brian

Thompson.

8

The Report of the evaluation was circulated in May 2006. This report consisted of thirty seven (37) recommendations categorised as per items (i) to (v) in paragraph 1. The Council was not in full agreement with the recommendations and at the last Council Meeting reviewed the recommendations and formulated a response. The response will be submitted to SEDI/FEMCIDI. It should be noted that the Project was designed and executed in accordance with the guidelines supplied by SEDI/FEMCIDI.

SIM Project 2005-2008 - "Implementation of

metrology Infrastructures of the Americas to support Free Trade and Quality of Life"

The first year and a half of this Project has had its challenges and as a result we have had to reorganise the scheduled activities. In addition, there were quite a few pertinent changes at Member NMIs and this slowed members' active participation initially and as such some of the planned activities were not accomplished. Internationally the field of Metrology is becoming more prominent, especially in the international trade arena and more of members' time has to be devoted to resolving issues of technical barriers to trade. Nevertheless, it is my sincere belief that SIM will continue in it quest to build the Metrology Infrastructure of the Americas, and to provide training and technical assistance in order that developing NMIs can participate in the hemispheric and international trade arena without their measurement deficiency being used against them as a technical barrier to trade.

SIM's Participation in International Metrology Events

SIM continued to participate in various international and regional metrology activities. Of particular importance this year is our participation in the launching of AFRIMETS (The African Metrology System), in Pretoria, South Africa, which it is proposed may be based on the SIM Structure with some of the same aims and objectives since the composition of members' (AFRIMETS) capability is similar to that of SIM's. The coming into being of this RMO is a big plus for Metrology world wide as it would allow interaction and collaboration in a region where presently we are not very active. Also of note is our continued active participation in the JCRB Meetings and the leading role that SIM is playing in shaping the quality systems review process. For this, I wish to say special thanks to the QSTF, the QSTF Chairman and the JCRB Representatives.

SIM Activities of 2004/2005

There have been a number of activities during the past year, two Council Meetings, training activities in Trinidad and Tobago during the last GA; training activities in Central America and South America, and activities of the

Chemical Metrology Project. Once again I wish to thank all those who worked tirelessly to make all these events successful. We continue to participate in the NCSLI Conference, by having our display booth and through our representative to the NCSLI Board of Directors. This is a great learning experience, the workshops and talks are invaluable and I encourage all members to make and effort to participate. We have been in discussion with some of our sister/brother organisations (KEBS, ASTM..) who wish to become associate members/observers of the SIM GA. We hope to complete these arrangements shortly. Last year's GA was organised by Mr Theodore Reddock and his team for the Trinidad and Tobago Bureau of Standards and we thank them and the Government and people of Trinidad and Tobago for being such gracious hosts.

Shortly after the last GA, Dr Stephen Carpenter announced his retirement from NIST after a long and distinguished career, and after many years as the SIM Technical Advisor. We were indeed saddened to learn that he had retired but as fate would have it he has been contracted by NIST to continue as the SIM TA. Dr Claire Saundry provided technical support services in the interim for which we are very grateful and we look forward to a continued fruitful working relationship with both Dr Carpenter and Dr Saundry. I would also like to congratulate Sally Bruce of NIST who has been appointed Chief of NVLAP and our NCSLI Representative on the SIM Council, Mr Steve Stahley who has been elected to the National Cooperation for Laboratory Accreditation (NACLA) Board of Directors/Operations Council. During the year Dr Yoshito Mitani, our Professional Development Chairman for many years announced that he was demitting office. We thank him for his work over the years and wish him every success in the future. While we have made some progress in the last year, it is possible to achieve much more. But this requires greater commitment and dedication to the work of SIM. I fully understand that we each have our own national commitments; however we must view our commitment to the work of SIM and the development of metrology regionally and internationally as means of developing our national infrastructures. Members need to take more responsibility and become more active in the work of SIM.

In conclusion I am grateful to INMETRO for their willingness to host the Secretariat during my tenure. I also say special thanks to Taynah Lopez of INMETRO, for the work she had done as the SIM Secretary. I imagine it was not an easy task for her since INMETRO is also hosting the IMEKO Conference 2006 in conjunction at the same time. I look forward to the deliberations of this year's GA and I wish us all every success.

Dianne Lalla-RodriguesSIM President2004-2006

9

WATT BALANCES AND THE FUTURE OF THE KILOGRAM

Michael Stock Bureau International des Poids et Mesures (BIPM)Pavillon de Breteuil, 92312 Sèvres CEDEX, France

Tel.: +33 1 4507 7070 Fax: +33 1 4534 2021 email: mstock@bipm.org

Abstract: The kilogram is the only base unit of the SI system still defined by a material artefact. A number of laboratories are working on experiments to replace the current definition by one based on fundamental constants. The paper gives an overview over these techniques with special emphasis on watt balances. The BIPM, being the custodian of the international prototype of the kilogram, has recently started to develop a watt balance whose distinctive features are described. The paper concludes with an overview of the existing experimental results and their implications for the evolution of the kilogram definition and of the SI as a whole.

1. INTRODUCTION

The kilogram is the last base unit of the SI system still defined by a material artefact, the international prototype of the kilogram, kept at the BIPM.

The international prototype has served mass metrology very well over more than 100 years [1]. Nevertheless, an artefact standard for the mass unit has a number of disadvantages. It is only available at a single place and the mass unit cannot be realized elsewhere. It can be damaged or destroyed. An artefact standard can accumulate contamination and needs to be cleaned with incompletely known effects. Since the creation of the BIPM in 1875, three comparisons have been carried out between the international prototype and its six official copies. The masses of the official copies seem to increase relative to the international prototype at a rate of about 5 parts in

810 over 100 years. There is no reason to expect that the mass of the international prototype is more stable than those of its official copies. The question of stability can only be definitely answered by an experiment linking the international prototype to an unalterable fundamental constant of nature, with an

8uncertainty of the order of 1 part in 10 .

2. LINKING THE KILOGRAM TO FUNDAMENTAL CONSTANTS

The kilogram can be linked to different fundamental constants or atomic masses. The most obvious approach is to compare the mass of a known and very large number of atoms of the same type with a macroscopic mass. This establishes the kilogram as a known multiple of an

atomic mass, which is equivalent to a determination of the Avogadro constant N if the A

molar mass of the atoms is known. The difficulty lies in collecting a sufficiently large, and exactly known, number of atoms for the weighing operation. Two different approaches are currently pursued. The PTB is developing an experiment in which a weighable mass is accumulated from gold or bismuth ions delivered by an ion beam [2]. The number of ions is determined from an integration of the beam current over time. The uncertainties

3are currently of the order of 1 part in 10 . A significant improvement is expected from work focusing on increasing the ion beam current. An alternative approach is to determine the number of silicon atoms in a nearly perfect single-crystal silicon sphere. The number of atoms is deduced from the volume of the unit cell and the volume of the whole sphere. This project is carried out as an international collaboration of several institutes. The uncertainty of this technique, named X-ray crystal density method (XRCD), is currently limited by the determination of the isotopic composition of

7the sphere to about 3 parts in 10 [3]. Future experiments are planned with a sphere made of at

28least 99.99 % Si, and uncertainties of several 8parts in 10 are expected.

Another class of electro-mechanical techniques links the kilogram to the Planck constant h. The most successful experiment of this type is the watt balance. The principle is explained in the next section. Five research groups are working on this technique, and in 2005 the NIST announced that

8they had reached an uncertainty of 5 parts in 10 . Further progress seems possible. Therefore watt balances appear nowadays as the most promising approach for a redefinition of the kilogram.

10

3. WATT BALANCES

3.1 The principle

A watt balance compares a measurement of electrical and mechanical power. The electrical quantities are measured based on macroscopic quantum effects, the Josephson effect and the quantum Hall effect [4]. These two effects link the electrical quantities to fundamental constants and allow one to establish a relation between a macroscopic mass, measured in the unit kilogram, and the Planck constant h.

A watt balance experiment consists of two parts, the “weighing experiment” and the “moving experiment”. In the weighing experiment (Fig. 1) the gravitational force on a mass m (its weight) is balanced by the Lorentz force on a coil with wire length L, carrying a current I, in a magnetic field with flux density B. If equilibrium is obtained the equation

BLIgm =

IB

F =

I

L

B

m

F

=

m

gel m

Figure 1: Weighing experiment: An equilibrium between gravitational force and Lorentz force is

established.

In the moving experiment, the same coil is moved at constant velocity v though the same magnetic field as before (Fig. 2). An induced voltage e appears across the coil which is given by

(1)

(2)

(3)

(4)

BLv=e

Both equations can be combined by eliminating the quantities describing the coil, L, and the magnetic field, B, resulting in

IUvgm =

This equation demonstrates that electrical and mechanical power are directly compared. It is, however, important to notice that these powers are virtual. They are not realized as a real power, because the current I and the voltage U are measured in different phases of the experiment. The same is true for the mechanical power. This

has the important consequence that power losses during the movement, for example due to mechanical friction, do not appear directly in the measurement equation.

B

e = B L v

e

v

Figure 2: Moving experiment: A voltage is induced by moving the coil with constant velocity

through the magnetic field.

To bring in the Planck constant, the electrical quantities are measured using the conventional electrical unit system based on the Josephson and the quantum Hall effect [4]. The Josephson effect allows one to realize a reproducible voltage over a junction between two superconductors irradiated with microwaves. The quantum Hall effect allows one to realize a reproducible resistance using a two-dimensional electron gas in a strong magnetic field. This leads to the following equation:

vg

IURKhm KJ 909090

290

4--=

K and R are the conventional values for the J-90 K-90

Josephson constant and the von Klitzing constant. U and I are, respectively, the voltage and the 90 90

current measured in the conventional electrical unit system.

This equation establishes the relationship between a mass m and the Planck constant h. At first, the experiment would be carried out to determine h, based on the current definition of the kilogram. If the uncertainty has been reduced to

8several parts in 10 and the metrology community feels sufficiently confident about the results, the best value obtained can be used to define the value of the Planck constant (without uncertainty), this being equivalent to redefining the kilogram.

3.2 The existing experiments

In the following, the main characteristics of the existing experiments are described briefly; more details are given in [5]. The BIPM watt balance is described in more detail in section 4.

11

The NPL (UK) began to construct the first watt balance soon after the original proposal by B. Kibble [6] in 1975. The balance is constructed as a classical beam balance and the magnetic field is produced by a permanent magnet. Results obtained with the first version of the apparatus had

7a standard uncertainty of 2 parts in 10 and were published in 1990 [7]. The current second version will be replaced by the Mark III balance in the near future.

The NIST (USA) started its experiment only a few years later with an electromagnet, which was subsequently replaced by a superconducting magnet. Instead of a balance beam a rotating wheel is used which restricts the movement of the coil to the vertical axis. In 1998, results with an

8uncertainty of 9 parts in 10 were published [8]. Further improvements allowed to reduce the

8uncertainty to 5 parts in 10 in 2005 [9]. Both results are in good agreement. A further reduction of the uncertainty is expected in the near future.

METAS (Switzerland) started its watt balance project in 1997. The most obvious difference from the other experiments is the small size of the apparatus as a consequence of using a test mass of only 0.1 kg instead of 1 kg [5]. During the moving experiment, the test mass is decoupled from the mass comparator, to reduce hysteretic problems.

The LNE (France) started to develop its watt balance in 1999. This will be a medium-size apparatus working with a mass of 0.5 kg [10]. One of the design criteria was to avoid an unbalance of the mass comparator during the moving mode. This will be achieved by moving the balance together with the coil. Many of the components of the experiment have been prepared and will be assembled in 2006.

4. THE BIPM WATT BALANCE

4.1 Design

For the validity of the basic equation (3), it is essential that the magnetic flux density B is the same in both parts of the experiment. The temperature coefficient of the remanent magnetization of SmCo magnets, used for the permanent magnets in the existing watt balances, is about 0.035 %/K. Therefore small temperature changes of the magnet lead to significant changes of the magnetic flux density. If both measurement phases are carried out sequentially, at a time interval of typically one hour, the magnetic flux density can therefore be significantly different.

At the BIPM we plan to carry out both parts of the experiment simultaneously. A constant current will be injected in the coil to create a magnetic force to balance the weight, while the coil is moving at constant velocity through the magnetic field. The induced voltage related to the movement will be superimposed on the voltage across the coil due to the current flow. Both types of voltages need to be separated with an uncertainty of the order of 1 part

8in 10 . Most critically in this respect is the large temperature coefficient of the electrical resistance of the coil, 0.4 %/K. Resistance changes due to temperature changes of the wire during the time for a measurement (of the order of 1 minute) would mask changes of the induced voltage. We therefore plan to use ultimately a superconducting coil in which the resistive voltage drop would not exist. In this “cryogenic watt balance” the permanent magnet will also be held at cryogenic temperature.

We have started to assemble a room temperature experiment to gain experience on the general feasibility of simultaneous force and velocity measurement, and to find out how much the uncertainty of such an experiment can be reduced. Only after this stage will we start to work on a cryogenic system.

4.2 Current Status

The assembly of the BIPM watt balance started in May 2005. We have started to build the balance suspension, which includes an electrostatic motor, moving the coil vertically (Fig. 3). The motor consists of a fixed, grounded central electrode and a mobile unit of two high voltage electrodes, above and below the central one. The electrostatic force between the grounded electrode and the high voltage electrodes leads to a vertical movement of the latter. This movement is translated to a vertical movement of the coil by 3 beams connected with flexure strips. The displacement range is about 20 mm. The force varies with the square root of the voltages and with the inverse square root of the distance between grounded and high-voltage electrodes. The voltage dependence can be linearized by applying the same bias voltage to both electrodes and by superimposing opposite voltage changes on both electrodes. We are currently working on a digital control system to control the vertical position and the velocity of the coil. The vertical displacement should not in t roduce any ro ta t ions or hor izonta l displacements of the coil. These are monitored by using position-sensitive detectors together with laser diodes.

12

Figure 3: Upper part of the suspension, showing the electrostatic motor and – close to the center -

the weight. The upper weight serves as counterweight to reduce the force on the motor.

We have developed a design for the magnetic circuit (Fig. 4). The most important criteria are a sufficiently high flux density, a high uniformity of the flux density within the gap, and a good sc reen ing aga ins t ex te rna l magne t i c perturbations. The flux source will be two discs of Sm Co with opposite magnetization. They will be 2 17

inserted in a closed magnetic circuit made of high permeability FeNi-alloy of austenitic structure, which does not become brittle at cryogenic temperature. A horizontal and radial field is obtained in the horizontal symmetry plane. The gap will be 13 mm wide with a diameter of 250 mm. The flux density in the gap, at the position of the coil is about 0.7 T. Since the gap is completely surrounded by material with high magnetic permeability, it should be efficiently screened against external magnetic fields. It is an important requirement that the flux density in the gap is constant in the vertical direction, so that the force on the moving coil does not change more that about 100 ppm. The system is symmetrical about the horizontal symmetry plane so that no linear slope of the field profile is expected. The inner and outer pole are 84 mm and 80 mm high. The small difference in height increases the uniformity of the field considerably.

The flux density in the gap depends critically on

its width, that is on the machining and assembly of the pole pieces.

Figure 4: The magnetic circuit, consisting of two discs of Sm Co and a closed FeNi yoke. The 2 17

flux density in the central plane, where the gap is located, is horizontal and radial.

The required uniformity demands that the width of the gap is constant within 6 mm. We are currently looking for a company capable of achieving this. The upper part of the magnet needs to be removable to give access to the coil. For the coil suspension, holes are needs in the upper part of the yoke.

We have developed a first version of a current source which delivers a current of 1 mA with a

7short term stability of about 2 parts in 10 . A 10 V monolithic voltage reference is connected in series with a 10 kW resistor, in which flows the current to be stabilized, at the input terminals of an operational amplifier. The output of the amplifier provides this current through a buffer amplifier.

To measure the coil velocity, we have purchased a commercial heterodyne interferometer, which is currently under test.

5. THE EVOLUTION OF THE SI SYSTEM

As described above, several institutes are working to establish a link between the international prototype of the kilogram and fundamental constants, as a first step towards a new definition of the kilogram.

An overview of the results of experimental determinations of the Planck constant h is given in Figure 5 (data taken from [11], which also includes references to the different experiments). The results NIM-95 and NPL-79 are obtained from

measurements of the gyromagnetic ratio of the shielded proton in a high magnetic field. NIST-80 is a measurement of the Faraday constant. PTB-91 and NML-89 are determinations of the Josephson constant K using a voltage balance and a liquid-J

mercury electrometer, respectively. N/P/I-03 is the determination of the Avogadro constant N by A

the Working Group on the Avogadro constant using the X-ray crystal density (XRCD) method. The results NPL-90, NIST-98 and NIST-05, having the smallest uncertainties, are obtained with watt balances.

NIS

T-0

5

NIS

T-8

0

PT

B-9

1

NM

L-8

9

N/P

/I-0

3

NP

L-9

0

NIS

T-9

8

NP

L-7

9

NIM

-95

5.5

6.5

7.5

8.5

[h/(

10

-34

Js)

-6.6

260]

x10

5

Figure 5: Experimental results for the Planck constant h, sorted according to the standard

uncertainty.

The most obvious feature of Figure 5 is the discrepancy of about 1 ppm between the watt balance results and that of the XRCD work. The origin of this difference is unclear. One of the greatest difficulties in the XRCD technique is the determination of the isotopic composition of the Si-sphere, necessary to obtain the molar mass. A new project has been started recently, eliminating

28this problem by using isotopically enriched Si. Results are expected by 2008. The target

8uncertainty is 2 parts in 10 .

Initiated by a recent publication which proposed to redefine the kilogram immediately [12], the Consultative Committees for Electricity and Magnetism (CCEM) and for Mass and Related Quantities (CCM) discussed this situation in 2005 and defined conditions which would allow a redefinition of the kilogram. The major obstacle is currently the discrepancy between the watt balance and the XRCD results. It is, however, expected that this discrepancy will be resolved during the next few years. The uncertainty of the best realization of the new definition should not

8exceed 2 parts in 10 , to ensure that the new definition is consistent with the present one within this uncertainty. It is expected that a mise en pratique would explain how the new definition can

be realized in practice. Besides the operation of a watt balance, this could include the comparison of an unknown mass standard with a known mass standard, whose mass itself was determined with a watt balance.

In addition to this, redefinitions of the ampere, the kelvin and the mole are proposed [13]. The International Committee for Weights and Measures (CIPM) made a recommendation in 2005 which describes the preparative steps towards these new definitions. In particular it recommends that National Metrology Institutes should pursue vigorously their current projects to obtain values for the fundamental constants with sufficiently low uncertainty and that they should prepare for long-term maintenance of the experiments needed to realize the new definitions. 6. CONCLUSIONS

Preparations have started recently for new definitions of the kilogram, the ampere, the kelvin and the mole. Further steps will depend on the progress with the related experiments, especially with watt balances, to determine the value of the Planck constant.

As shown in this article, the progress to date is encouraging, with one result having an estimated

8uncertainty of 5 parts in 10 . For the future, this uncertainty still needs to be reduced by a factor of 2 or 3, and the discrepancy between watt balance and XRCD results should be resolved. Other watt balance results with comparable uncertainties would also be highly desirable.

REFERENCES

[1] Davis R., Metrologia, 2003, 40, 299-305.[2] Gläser M., Metrologia, 2003, 40, 376-386.[3] Fujii K. et al., IEEE Trans. Instrum. Meas., 2005, vol. 54,

854-859. [4] Taylor B., Witt T., Metrologia, 1989, 26, 47-62.[5] Eichenberger A., Jeckelmann B., Richard P., Metrologia,

2003, 40, 356-365.[6] Kibble B., Atomic Masses and Fundamental Constants 5

(edited by J. H. Sanders and A. H. Wapstra), 1976, New York, Plenum Press, 545-551.

[7] Kibble B., Robinson I., Bellis J.H., Metrologia, 1990, 27, 173-192.

[8] Williams E., Steiner R., Newell D., Olsen P., Phys. Rev. Lett., vol. 81, no. 12, 1998, 2404-2407.

[9] Steiner R., Williams E., Newell D., Liu R., Metrologia, 2005, 42, 431-441.

[10] Genevès G., IEEE Trans. Instrum. Meas., 2005, vol. 54, 850-853.

[11] Mohr P., Taylor B., CODATA recommended values of the fundamental physical constants: 2002, Rev. Mod. Phys., vol. 77, no. 1, 2005.

[12] Mills I. et al., Metrologia, 2005, 42, 71-80.[13] Mills I. et al., Metrologia, 2006, 43, 227-246.

13

14

NIST -- PROMOTING INNOVATION, COMPETITIVENESS AND

FACILITATING TRADE

Hratch G. SemerjianNational Institute of Standards and Technology

Gaithersburg, MD, USA 20899-1000(301) 975-5555, hratch@nist.gov

Abstract: Measurement and standards infrastructure of a nation is critical for domestic and international trade; but it is also important for fostering innovation and facilitating the transition of scientific discoveries into the market place. The role of measurements and standards provided by NIST is becoming ever more important as economic development and job creation increasingly rely on advances in high technology manufacturing processes and products. Historical role of metrology in facilitating trade is reviewed, and examples on the increasing role of metrology in promoting innovation and competitiveness are presented.

1. INTRODUCTION

The physical infrastructure of a country, e.g., the highways and bridges, the air traffic management system, the electrical grid and water supply systems, is usually taken for granted; citizens notice the infrastructure only when there is a problem, because it affects our daily lives. The measurement and standards infrastructure is equally important and also taken for granted; we assume that we are getting what we paid for in the marketplace, when we buy food at the grocery store, fill up our car at the gas station, or pay our electric or water bills. And we assume that we can sell our products anywhere in the world; it is extremely distressing for a manufacturer to find out that its product is not accepted in another country, because of non-compliance with certain standards. There is even a lesser appreciation of the importance of the measurement and standards infrastructure for a nation's innovation capacity and competitiveness in the global marketplace. It is important to articulate the critical role of measurements and standards in promoting innovation, industrial competitiveness, and contributing to the economic growth of a nation.

2. HISTORIC ROLE OF METROLOGY

Before discussing the role of metrology into the future, we should take a look at where all this began. The earliest known uniform systems of weights and measures date back 5,000 years to the Bronze Age and the ancient peoples of Mesopotamia, Egypt, and the Indus Valley.

The critical importance to society in adopting a uniform set of weights and measures can be

demonstrated in that it appears to be a common discovery in virtually all cultures. Most early measurement systems used parts of the body and the natural surroundings. Length was first measured with the forearm, hand, or finger and time was measured by the periods of the sun, moon, and other heavenly bodies.

The cubit is perhaps the oldest and longest-lived example of a standard measurement unit. The oldest documented cubit is the Egyptian royal cubit—traced back to 2750 B.C. and used for about 3,000 years. And the Egyptians took their cubit seriously. In fact, it has been reported that: " The death penalty faced those who forgot or neglected their duty to calibrate the standard unit

1of length at each full moon...”

To measure volume, people would fill containers with plant seeds which were then counted. When means for weighing were invented, seeds served as standards. For instance, the carat, still used as a unit for gems, was derived from the carob seed.

In China, some 3,500 years ago, a system of standard instruments for measuring length, mass, and volume was created. A special organization was established with the responsibility for checking the accuracy of these instruments twice a year. The Chinese may also have been the first to use an unvarying physical constant as a standard of measure. Similar to the way we now use the distance light travels in a second as a length standard, 2,700 years ago the Chinese used the resonance tone of bamboo whistles to

2ascertain a length standard.

The good news is that every country, region, and city-state recognized the need for a uniform set of weights and measures. The bad news is that virtually every commercial center developed its

15

own unique measurement system making commerce between trading centers cumbersome.

The problems and confusion caused by this measurement menagerie did not go unnoticed. In 1196, King Richard I of England proclaimed in the Assize of Measures that “…throughout the realm there shall be the same yard of the same size and it should be or iron”, and had yard standards, in the form of iron rods, distributed throughout the country. The expression “by the King's iron rod,” referring to the yard, appears frequently in historic records. Shortly after in 1215, The Magna Carta called for "one measure for ale, one measure for wine, one measure for corn”, declaring the need for uniform standards for length, mass, and volume standards..

But the problem continued to grow. In 1788, France had about 800 different names for measures and, taking into account their different values in different towns, resulted in around a quarter of a million different units. The Metre Convention, signed in 1875, represents the starting point towards harmonization of measurement standards.

In the U.S., the responsibility for uniform weights and measures was assigned to the federal government. In the U.S. Constitution, Article I, Section 8 states that “The Congress shall have the power to…coin money, regulate the value thereof, and of foreign coin, and fix the standard of weights and measures”.

During the Industrial Revolution, with the development of the steam engine, the locomotive, the steamboat, electricity, the telegraph, and the telephone, the need for accurate measurement increased. In 1900, the American electrical industry represented an investment of $200 million, but growth was inhibited by a lack of recognized standards, which contributed to frequent and costly litigation. The magazine Scientific American warned that a national laboratory had become “a national need”. The National Bureau of Standards (now NIST) was finally established in 1901.

3. METROLOGY LEADING TO INNOVATIONS

Since then, NIST's mission has been, and continues to be, “to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life”.

The pivotal role NIST plays in the U.S. economy is illustrated in Fig 1. In its more traditional role, NIST has provided the measurement science and standards that have ensured equity in trade and transaction efficiency; more recently, these tools have become critical to ensure access to the global markets. However, NIST role in developing new measurement capabilities and technology have become even more important for the competitiveness of U.S. industry, by making them more productive and their products accepted in the global markets. The improved measurement science capabilities also make the U.S. R&D enterprise more efficient and more innovative, leading to improved quality of life for U.S. citizens.

From its inception, NIST has addressed measurement and standards issues of national importance. Shortly after the National Bureau of Standards was established, it was asked to provide “Standard Samples” for the American Foundrymen's Association, including various types of iron samples which were certified for chemical composition, in order to ensure the uniformity of cast iron that was used for railroad cars and tracks. Chemical measurements have changed a great deal since then. Instead of wet chemistry, sophisticated new methods such as Isotope Dilution Mass Spectrometry (IDMS) are being used for detailed characterization of super alloys, which are used in gas turbine engines, as well as for measurement of sulfur content in fossil

3,4 fuels . New chemical measurements are also playing a crucial role in improving health care, by enhancing the accuracy of clinical measurements, for example, for cholesterol and more recently for

5,6troponin . These measurements and standards are also critical to meet regulatory requirements promulgated by the European Union for in vitro

7diagnostic devices.

NIST OUTPUTS

Metrology

Standards

Technology OUTCOMES

Innovation

Competitiveness

Trade

Industry

Commerce

R & D

CUSTOMERS

Productivity

Market Access

Quality of Life

Fig. 1 – NIST's pivotal role in the U.S. economy

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Another example of how measurements foster innovation -- and one that is used by many in the scientific community -- is the Mass Spectral Library. This is a database NIST has developed that contains information about more than 160,000 chemical compounds. While originally expected to be used primarily for environmental and health applications -- industry has found novel ways of applying that data to forensics, homeland security, food and flavors research, and industrial quality control. This technology has now been extended

8to include peptides and proteins , with potential applications in clinical measurements and health care. This is a great example of how a basic infrastructural component - in this case spectral data - can be leveraged and used in many applications.

For many years, electrical measurements have been of critical importance for a broad range of industries, including power generation, electronics, instrumentation and communications industries. In 1910, the BIPM International Technical Committee established new values for the international ampere, ohm, and volt, based on measurements using a silver voltmeter. Today, an intrinsic standard using a Josephson Junction voltage standard chip (a chip that is 1 cm x 2 cm and contains 20,208 Nb-AlOx -Nb junctions that are serially connected) is the basis for most of the voltage measurements (see Fig. 2a). More recently, NIST has succeeded in making the first 5-junction stacks of Josephson Junctions to further

9,10improve this technology .

To meet future measurement needs, NIST has developed the world's most accurate electron counter as a new standard for capacitance. This counter can place 70 million electrons on a capacitor with an uncertainty of just one electron (see Fig. 2b). The heart of the counter is a special microcircuit that “pumps” electrons one at a time to a capacitor. In the figure, the bullet-shaped regions in the center are micrometer-sized islands of aluminum, separated by tiny “tunnel junctions of aluminum oxide. The capacitance of the islands is so small that at temperatures near absolute zero (less than 0.1 K) only one excess electron can

11occupy a given island at a time .

Another example of how measurement science enables innovation is the work of NIST's most recent Nobel Laureate, Dr. Jan Hall. Dr. Hall transformed the laser from a laboratory curiosity to one of the fundamental tools of modern science. His research improved the accuracy and stability with which lasers generate a specific frequency of light. Through his research, the laser frequency itself became a research tool with an accuracy of 1

15part in 10 !

The development of the laser as a measurement tool enabled a series of innovations and resulted in the creation of whole new industries. These innovations include fiber-optic communications; vastly improved clocks which enable accurate navigation; precision spectroscopy for detecting minute quantities of a substance; and measurements of fundamental physical constants.

And better measurements continue to open up new windows on the world. Consider the developments in the measurement of time. In 1904, the NBS pendulum clock had an accuracy of

-91 second in 3 years (10 ). In 1949, NIST introduced the world's first "atomic clock," accurate to one second in 300 years. Today, its accuracy is about one second in 60 million years

-15(10 ). And, we are looking ahead to an optical clock accurate to about one second in 30 billion years! Clearly, back in 1949, we could not have predicted that NIST's atomic clocks would be used for setting time on personal computers and guiding deep space probes. Or that the National Association of Securities Dealers would require that all electronic transactions be stamped with a time traceable to NIST. Telecommunications, electric power transmission, transportation, and navigation (including support of the Global Positioning System) all rely on NIST time. This is just another example of innovations enabled by measurement science.

Fig. 2 – New standards for electrical measurements - a) NIST 10 V Josephson Junction Standard; b) New standard for capacitance measurements.

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But, how do we know that measurements and standards play such an important role in terms of our economic competitiveness? Well, like everything else at NIST - we measure it.

NIST has conducted 19 economic studies to assess our impact on industry. These studies document an average direct return to the economy

12of $44 for every $1 spent by NIST .

Our work to develop standard reference materials for measuring the sulfur content of fuels, for example, led to improved efficiency and lower transaction costs in the fuel industry. This research

13led to a benefit-to-cost ratio of about 113 to one .

One of the lower economic impacts we found was developing the chemical and thermodynamic datasets for alternative refrigerants. The impetus for this research was the need to quickly replace ozone-destroying CFCs. Even with the objective being to develop "ozone friendly" refrigerants - we still achieved an economic benefit-to-cost ratio of about four to one on top of the environmental

14benefits .

NIST is able to demonstrate such large benefits to the Nation because it contributes to the innovation infrastructure of the economy. Advances NIST makes support whole industries or sectors -- as opposed to supporting an individual company. Thus, our advances are leveraged by large segments of the economy creating a favorable multiplier.

4. METROLOGY AND INNOVATION IN THE 21st CENTURY

There is general agreement that if you can't measure something -- you can't control it. And if you can't control it - you can't reliably manufacture it. NIST's unique role is to advance measurements and standards so that the next innovation can be realized and commercialized. Innovations in emerg ing techno logy a reas such as nanoelectronics, nanomanufacturing, fuel cells, biotechnology, renewable energy sources, and quantum information will be highly dependent on advances in related measurement science. NIST has expanded its efforts to develop the measurement science and standards that support innovation and economic competitiveness in such emerging technology areas.

Experts predict that, within the next ten years, at least half of the newly designed advanced materials and manufacturing processes will be products of nanotechnology. The global industry of nanotechnology is predicted to exceed $1 trillion by 2015. Today, "low tech" nanoparticles are already prevalent - from titanium dioxide particles

in sunscreen to block out UV while transmitting the visible (and hence appear transparent) to hydrophobic nanoparticles embedded in fabrics to make them stain resistant. These "low tech" nanoparticles are the first to make it into the marketplace because their manufacturing tolerances are relatively large. The size and purity of the particles do not have to be tightly controlled to effectively block UV or resist stains.

The next generation of nanoproducts, however, is likely to require tighter control on size and other properties. For example, if you want to produce a carbon nanotube of a specific length, width, and chirality - we currently have to produce a batch of nanotubes and sort through them to find the closest match. This is not a process that scales well to industry. Thus, we need to develop the measurement tools and the standards to facilitate the development of the next generation of nanoproducts.

NIST is already working on measurements to characterize devices with nanoscale features. Device features on computer chips as small as 40 nanometers (nm) wide - less than one-thousandth the width of a human hair – can now be measured reliably using new test structures developed by NIST, SEMATECH, and other collaborators. The test structures are replicated on reference materials that will allow better calibration of tools t h a t m o n i t o r t h e m a n u f a c t u r i n g o f microprocessors and similar integrated circuits. The new test structures are the culmination of NIST's more than five-year effort to provide standard “rulers” for measuring the narrowest linear features that can be controllably etched into a chip. The NIST rulers are precisely etched lines of crystalline silicon ranging in width from 40 nm to 275 nm. The spacing of atoms within the box-shaped silicon crystals is used like hash marks on a ruler to measure the dimensions of these test structures. Industry can use these reference materials to calibrate tools to reliably measure microprocessor-device gates, for example, which

15control the flow of electrical charges in chips .

Steps of silicon also serve as a natural ruler for measuring vertical dimensions. This silicon "target" has step heights ranging from tens to hundreds of nanometers leading down to a flat, single atomic layer measuring only 0.3 nanometer. The microscope used to make this image sits on an isolated concrete slab equipped with air springs to cancel out even minute vibrations that could ruin

16the nanoscale measurements (see Fig. 4a).

Using the interferometer-guided probe of the Molecular Measuring Machine, accurate calibration patterns can be produced. To create

18

this artifact, a writing method based on scanned probe oxidation of hydrogen terminated silicon

17was used (see Fig. 4b).

Tools for manipulating nanocomponents will also help accelerate research on the performance of new nanotechnologies. NIST researchers have developed new methods to manipulate nanowires with "optical tweezers." A highly focused laser beam attracts microscopic objects and can be used to pick up and precisely position nanocomponents for building semiconductor circuits or biosensors smaller than a red blood cell

Fig. 4 - Nanorulers based on silicon technology

Researchers at NIST currently have requirements to measure force from picoNewtons to MegaNewtons (18 orders of magnitude). For example, NIST has a 4.4 MegaNewton deadweight machine that is used for testing the strength of bridge abutments. This is the largest such device in the world. But, how do you weigh a dust mite? Or determine the force required to pull a molecule apart? Such tasks require a device that measures nanoNewtons -- forces 1 billion times smaller than the force required to hold an apple against Earth's gravity. NanoNewton forces are estimated with atomic force microscopes and

instruments that measure the properties of ultrathin coatings like those used on computer hard drives or turbine blades. But the accuracy of such estimates is unknown because they haven't been calibrated with force standards based on the kilogram, the internationally accepted unit of mass.

But, help is on the way. NIST has developed a prototype instrument that reliably measures forces as small as tens of nanoNewtons and simultaneously ties those measurements to forces

18a thousand times larger based on the kilogram . The device works by connecting a well-calibrated spring-loaded scale with a set of electrodes that generates an electrostatic force. The instrument balances the downward force produced by a one-milligram mass artifact, by keeping the distance between the electrodes constant but varying the amount of voltage between them. The result is a force determination accurate to a few parts in 10,000 that is measured with voltage, electrical capacitance and distance (the location of the electrodes as measured in wavelengths of laser light). The NIST researchers hope to extend the instrument's resolution to tens of picoNewtons.

And as nanotechnology quickly evolves into a potentially trillion dollar industry over the next decade, the requirements for measuring mass and size at the smallest scales will become critical. We are not yet ready for the amazing potential that nanotechnology offers—so NIST, is again also accelerating its efforts in the development of nanometrology. NIST has also established a new Center for Nanoscale Science and Technology to make its measurement capabilities available for U.S. industry.

Whi le the breakthroughs occurr ing in nanotechnology are amazing, equally breath-taking developments may arise by exploiting purely quantum phenomena. Quantum mechanics plays at a scale where the normal laws of everyday experience break down and new phenomena arise. Through developments made in the last two decades, we are beginning to generate quantum phenomena at classical scales through creation of new forms of matter, like Bose-Einstein condensates which consist of a collection of atoms that behave as if described by a single wavefunction.

Researchers already are using quantum information science to generate "unbreakable" codes for ultra-secure encryption. They may someday build quantum computers that can solve problems in seconds that today's best supercomputers could not solve in years. And, the potential of exploiting the quantum phenomena for developing new detectors, tools, and other

19

19devices is just starting to be tapped .

With several world-renowned scientists, including three Nobel laureates, NIST is well-positioned to develop the tools for measuring and controlling these quantum phenomena and harnessing their properties to benefit the nation. Our work is widely recognized as one of the most advanced quantum research programs in the world.

Renewable fuels, fuel cells Ref. 20….

Biotechnology is another area of explosive growth. Sequencing of DNA has opened up an entirely new horizon for gene therapy. This will require accurate measurements of gene expression. NIST is working with industry….Ref. 21.

These examples illustrate that innovation -- enabled by U.S. investment in basic science -- will continue to drive our economic security and enhance our quality of life.

5. LOOKING TO THE FUTURE22The American Competitiveness Initiative

announced in February 2006 recognizes the critical role that NIST plays in the development of the U.S. innovation infrastructure. The ACI will give NIST the resources needed to provide U.S. industry and the scientific community with the measurement and standards tools they need to maintain and enhance our global competitiveness.

Specifically, NIST will be concentrating in four thematic areas:1. Targeting the most strategic and rapidly

developing technologies -- such as nanotechnology, quantum information science, building the hydrogen economy, and cybersecurity.

2. Increasing the capacity and capability of critical national scientific assets -- by expanding its Center for Neutron Research, and upgrading and expanding the NIST presence at the DOE National Synchrotron Light Source at Brookhaven.

3. Meeting the Nation's most immediate measurement needs -- by addressing manufacturing supply chain interoperability, building codes and standards to minimize losses due to natural disasters, and expand our efforts in international standards, biometrics, and medical imaging

4. Improving NIST physical facilities -- by upgrading some of the older buildings -- so that the physical environment (temperature, humidity, vibration, and cleanliness) does not become the ultimate limit to our measurement accuracy.

REFERENCES

[1] Metrology - in Short, 2nd edition, 2003; a European Union publication

[2] Yenming Zhang, A Concise History of Ancient Chinese Measures and Weights, 2005

20

NMIJ STRATEGIES TO FACE THE INCREASING NEEDS IN

METROLOGY

Mitsuru TANAKANational Metrology Institute of Japan

3-9, AISTCentral, 1-Umezono, Tsukuba,Ibaraki,JAPANnmijtanaka@m.aist.go.jp

Abstract: Japanese NMI is on the way to establish around 500 measurement standards by 2010 according to the national program for metrological standards, has already been successful in more than 450 items and expected to complete the target in advance to the schedule. However, the recently emerging regulatory needs for sustainable society requires far wider scope in the program as seen in chemical reference materials and forces the NMI practical measures. In order also to deliver the provision of measurement standards to its end user, the NMI is required to be still active in fostering accredited calibration laboratory, facilitation of new calibration service and development of technology expanding the scope of reliability in measurement according to cost and delivery time allowed to end users. Its new strategy aims these objectives done under close cooperation with National Accreditation Body and the government.

1. BACKGROUND

Competitiveness in industrial products and technologies and their cooperation are facilitated by the reliability of measurements. The needs for their improvements and maintenance of the rel iabi l i ty sometimes force renewal of measurement standards and their dissemination system in terms of legislation and global acceptance. In 90's, Japanese government implemented the establishment of the national measurement system guaranteeing the globally accepted result of measurement and its technical infrastructure. Implementation of the program, JCSS (Japan Calibration Service System) includes, renewal of metrology institutes, which had long been serving for the legal metrology, effective measurement law allowing the governmental accreditation on quality of calibration services in private laboratories, dissemination of national measurement standards conforming to international standards and the dissemination of the concept of traceability.

The metrology institutes were unified to NMIJ in 2001 and the national accreditation service started for the calibration laboratories. The national program listed 500 measurement standards to be developed and disseminated by 2010. Among many dissemination activities for the concept of traceability to potential metrological sector, the publication of the list with detailed schedule was appreciated to be most effective. The NMIJ, having the governmental supports, expanded its size, enhanced its activities and has successfully achieved its mission according to the program. Now, at the beginning of Fy 2006, it has successfully established more than 450 items in

the lists. The achievement convinces the metrological sectors of benefit of broad utilization of the national measurement standards and facilitated their creative business in new technical services.

The contents of the national program was initially fixed according to the requests from the metrological sectors (such as semi-governmental authorities for testing services and leading measuring instrument manufacturers), the list of key comparisons and CMCs planned in CIPM-MRA and the calibration lists in other countries. After the initial phase of the program, the output of the dialogues with metrological sectors, intended to have the program responding correctly to the requests from end users in the industries, studied on evolution of measurement technologies in the industries and on progress of international societies for certification and standards have had to be continuously fed to the maintenance of the program. The Metrology Management Center (MMC) of NMIJ serves for the maintenance on the program and controls the progress in the laboratories of NMIJ engaged in the development by monthly interviews. Stimulated by the achievement of NMIJ, the quality assurance sections in the big manufacturers capable of high level calibration joined the JCSS and some of them began new calibration business for other industries. Other new calibration businesses for lower level calibration service or using higher level calibration service were created, too.

The measuring instrument manufacturers has 0.5% share in national GDP and 10% of their products are exported, while the same portion of measuring instruments are imported. This

21

industrial sector has the highest interest by nature to JCSS.

NMIJ is playing important technical roles in the mutual acceptance arrangement (MAA) for global legal metrology societies and the successful cooperation between NMIJ and weighing instrument manufacturers for the national traceability system achieves great contribution for the role.

2. INCREASING NEEDS AND HOW NMIJ PLANS TO RESPOND TOTHEM

250 out of 500 items for the program is reference materials for chemical analysis and the program had been aware from the beginning insufficient scope for the end user of chemical analysis over whole national needs. The scope of items were then subject to the affordable hum an resources of chemistry section of NMIJ and limited to basic chemical reference materials for general purpose, for leading edge industries and environmental regulations. Inorganic standard solutions, pH standards, gas analysis standards, environmental compounds, high polymer, nano-materials traceable to SI are all related to the manufacturing i n d u s t r i e s f o r t h e i r r e g u l a t i o n s a n d competitiveness. The items for regulations on other industries and society, such fields as water, air, soil and waste pollutions, product liability, food safety, medical diagnostics and biological safety, could not be counted.

The technical support for the metrological sectors contributing to the national metrology system is still important subjects addressed to NMIJ in order to facilitate the application of traceability. Development of calibration technology with automated system, training on calibration technique, on the uncertainty analysis and for quality control on the service and application of internet for the calibration are all direct contributions of NMIJ. Among them are special urgent request for new national measurement standard mostly from regulatory authorities. Calibration standards and technology of NMIJ for the ear radiation thermometers used for screening the patients of SARS timely helped the quarantine authorities in south and east Asian countries. Development of reference materials for the analytical testing in implementing RoHS directive, rf power measurement standards in a high frequency bands range necessary to quite urgent implementat ion of new legis lat ion for telecommunication regulation, high capacity water meter national standards for cooling regulation in nuclear plants and various measurement

standards for fuel cell evaluation are other example of urgent needs successfully responded by NMIJ. Systematic management on high potential researchers can allow such quick responses to order-made measurement standards from demanding request.

Although the implementation of CIPM-MRA started, the expansion of the scope and improvement in the environments for sound utilization of its benefit are still international problems. The certification on the quality of the products from domestic industries and the technology transfer over the border needs the close dialogues with the NMI on the other side in order to facilitate the practical application of the product of mutual recognition to quality assurance between end users over the border. For example, a new production line of automobile manufacturer transferred to foreign country has to establish their traceability path to NMI there and make parts industries there understand how to comply to the traceability requirements on their products under cooperation with other NMI.

2.1. FACILITATION IN APPLICATION OF TRACEABILITY AND STUDY ON NEEDS AND, IMPACTS

The increase in new items of measurement standards must be planned with prioritization based on the needs and impact study over the end users. So far, metrology management center of NMIJ circulated many questionnaires to metrological sectors (DI, Measuring instrument manufacturers, calibration laboratories and local metrological authorities) and fed the results of their analysis on the maintenance of the program. However, the technical fields investigated were limited to the manufacturing industries and the sectors were to the metrological sectors whose responses were quite reasonable because they were well aware what traceability does mean but could not foresee quite changeable and ambiguous needs of end users. Questionnaire study will not work in polling the needs of end users unless they are aware of traceability and the relationship of JCSS to the quality of their products. Detailed dialogues with end user only can predict the national needs for the measurement standards and consequently to global standards.

NMIJ has started metrology club system since last year for close dialogues in individual metrology field by encouraging the researchers to disseminate the concept of traceability in their own field, to transfer the measurement technology, to

22

investigate the needs at end user to measurement standards and technology and to estimate the impact of their measurement standards. After one year's operation, more than 30 clubs were established with total 1000 members from industries, regulatory sectors and consumers association as well as the metrological sectors. Each club corresponds to the consultative committee and its technical working group and the globally and regionally international activities for traceability are all reported to members and their needs are all fed to international and domestic policy of the government. This bottom up mechanism of the club works in various functions as had been successfully experienced in NPL and KRISS.

Domestic publicity activity is getting much more important especially for the measurement standards applied exclusively domestic end users or, sometimes, end users oriented to a specific technical field.

Counting the resources for establishing SI traceability for national measurement standard or establishing mutual recognition with foreign NMI, these local or bottom up measurement standards cost less resources and spend practically short time while the users must be well informed of the direction of use and scope of application. The club activity supports sound traceability to such bottom up measurement standards.

For example, a widely used and high-quality reagent with assigned calibration result can be national reference material as a source of traceability for comparability in a specific chemical field. It must be assumed that no other reference material authorized either as SI traceable or internationally recognized status is present in the countries, also that the process of calibration is reasonable, still also that the stability and uniformity are clear. The recognition in the specific field of users will facilitate quality assurance of end users in the field using common scale over the field. NMIJ has started new service to evaluate the quality of such bottom up measurement standards and notify it as domestically acceptable source of traceability, starting with the notification on the reference material for dioxin used for implementation of a Japanese Industrial Standards for regulation on the environmental fields.

The evaluation by NMIJ is based on the document submitted by the supplier of the reference material qualifying the level of quality control for safety, stability and uniformity and close study by NMIJ for

the traceability of the calibrated results and sometimes with experimental comparison for equivalence with those from other suppliers.

This service is certainly intended to meet increasing national needs for chemical field to the recognized source of traceability and also to facilitate R&D in the future for leveling up the status to SI traceability or international recognition.

As the recent outcome of club activities, national promotion program for new order-made calibration and testing service supporting manufacturing in small and medium enterprises was discussed in each club for possible new business in calibration and testing and more than 12 new businesses succeeded this year in winning the governmental financial support.

2.2. TECHNICAL COOPERATIONS WITH OTHER BODIES

The limited resources of NMIJ cannot allow it to disseminate whole measurement standards of national needs and the cooperation with other organizations are inevitable. The option, DI(Designated Institute), of CIPM-MRA functions helps NMIJ in giving them the international status. Whenever coordinating the roles of DI and accredited calibration laboratories, the evaluation on their technologies for calibration, administrative responsibilities and feasibility of economical management is critical because the calibration capability of private laboratories in Japan are as high as DI and in this respect, NMIJ must keep high metrological potential not only to disseminate the national measurement standards but also evaluate their high calibration technology.

The activity, mentioned in the last section, to evaluate and notify the national reference materials requires the same potential to NMIJ. In some case, the national research institutes engaged in other regulation sectors of other ministries with high potential in related scientific field, like food for example, collaborate with NMIJ to back up the evaluation of NMIJ. The disseminations also by such national institutes with DI status are envisaged. Most of notified reference materials for increasing needs are to be disseminated by private industries, as seen in the case of dioxin, and several other candidates from two pharmaceutical industries are currently applying.

Being one of the research units in the larger organization, AIST (National Institute for

23

Advanced Industrial Science and Technology), NMIJ has a lot of daily chances to cooperate with other research fields, such as environmental, energy-related, information, device and bio- technologies. It participates in the wider project of AIST to establish technical base for evaluation and regulation on the influence of nano-technology to human and other living bodies by developing physical property reference materials of nano-particles and carbon nano-tube, and also, by supplying them to other cooperated research units. The cooperation with information technology units allows NMIJ to develop the technology for verification and authentication on the software in measuring instruments and calibration technology. Those with device units provides NMIJ with Josephson Array for voltage standards and silica layer reference materials with highly controlled interface with silicon substrate and, with biological units, gives, analytical technology necessary for DNA quantification and cooperation for metrology in bio-luminescence.

2.3. INTERNATIONAL COOPERATION

Cooperation with other NMIs is one of important responsibility of NMIJ for international activities of domestic industries and society of Japan, such as trading and technology transfer. Especially, experience of active participation to global and regional metrology society since conclusion of CIPM-MRA contributed greatly to implant international view points to all researchers in NMIJ. The requirements for participation to key comparison and for transparent evaluation on the quality system have been advocated by NMIJ, and will be so in the future, to international society and to NMIJ itself to be met for CMC registration.

In order also to support the quality assurance of manufacturing industries in the factory transferred to foreign countries, NMIJ must cooperate with NMIs there not only in mutual recognition on national measurement standards but also in facilitating the training on quality evaluation for the parts industries supplying to the factory and sometimes the communication of the industries with the metrological society there. Such cooperation with NMIs in ASEAN countries for supporting international industries and with NIM of China especially for Shang-hai area has been quite productive for the last 5 years. In order to study general needs and impacts of international industries, a new club activity of NMIJ is planned.

As for the technical contribution to the improvement of global measurement standards, NMIJ conducts several projects with around 5

years term. Spectroscopy for atoms on the optical lattice for optical frequency standards, calibration technology by optical comb for wider range in optical frequency, programmable Josephson voltage standards using Josephson array, ultra-high temperature fixed points using eutectic alloy melts, determination of Avogadro constant for new definition of the kilogram and determination of viscosity of water are going on in NMIJ.

Recently NMIJ finished the first phase of the project “E-trace” intended to provide fast and cheap calibration tool using remote IT technology and together with the second phase for finalization, it proposes the mutual recognition by international metrology society to the application of the technology. The main concept is to enable the remote calibration, remote evaluation on the transfer standard and remote-operated support for reviewing in accreditation, by direct transfer of calibrated measurand converted to frequency or phase of cw signal, by transfer of digital information of the result of measurement and by transfer of the environmental and operation information for the calibration. The project was successful in developing and evaluation on calibration apparatus for remote site and on the stable and compact transfer standards for many measurement standards applications and practical application to frequency calibration in measuring instrument manufacturer in Shang-hai, optical interferometer in precision engineering manufacturer, calibration in AC/DC converter, calibration on 3DCMM, calibration on platinum thermometer and fixed point.

3.CONCLUSION

Many national measurement systems traceable to NMI and recognized by CIPM-MRA have been created and started their operation over the world but still needs facilitation for complete and effective implementation lead by NMIs. The geographic facilitation needs closer international cooperation between NMIs and the facilitation over whole range of industrial fields and social regulations needs the cooperation of NMI with other technological societies. Current major issues for all NMIs are a number of missing reference materials waiting for this facilitation. We, NMIs, still have missions for never ending facilitation for application of traceability system by publicity, training and needs and impact study.

NMI society will cooperate in these facilitations and will be successful in providing wide range of choice to the end users according to cost, time of delivery and reliability of measurement results.

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Fig.1. National Program for Establishing National Measurement Standards.

Fig.2. Facilitations for Increasing Needs

25

INTERLABORATORY MASS COMPARISON BETWEEN

LABORATORIES BELONGING TO SIM –SUB-REGIONS

COORDINATED BY CENAM (SIM.7.31a & SIM.7.31b)

1 1 2 2 3 3 4Jorge Nava , Luis O. Becerra , Tweedsmuir Mitchell , Mairy Sanz , Olman Ramos , Sandra Rodríguez , Gerson Vallejos , 4 5 5 6 6 7Marco Bautista , Francisco Garcia , Fernando Leyton , Aldo Quiroga , Juan G. Rodriguez , Ruben Ramirez , Arnoldo

7Florencio1 2 3CENAM–México, BSJ-Jamaica, LACOMET-Costa Rica,

4 5 6 7 7IBMETRO–Bolivia, CESMEC–Chile, INDECOPI-Peru, INTN–ParaguayTel: (+52) 442 2 11 05 00, Fax: (+52) 442 2 11 05 68, e-mail: jnava@cenam.mx, lbecerra@cenam.mx

Abstract: A round robin comparison in mass measurements between SIM member countries was carried out during the period April to November 2005. CENAM acted as pilot laboratory.

Six travelling standards with the following nominal values: 2 kg, 1 kg, 200 g, 50 g, 1 g and 200 mg were circulated. These travelling standards complied with the accuracy recommended for class E [1,2]. The results obtained are 2

represented in this report.

1. INTRODUCTION

A meeting of the technical contacts of SIM MWG 7 was held in Rio de Janeiro, Brazil in December 2004. At this meeting, subsequent to a proposal by the BSJ, planning was commenced for a mass comparison between SIM member countries in which at least one country from each sub region should participate. CENAM accepted the role as pilot laboratory for the mass compassion, as it had taken part in the key comparisons of the CCM of the CIPM.

The results of a comparison of six travelling standards among laboratories in the SIM region are presented in this report.

This program was coordinated by CENAM (Centro Nacional de Metrología), México. The travelling standards used are: 2 kg, 1 kg, 200 g, 50 g, 1 g and 200 mg, all of them are made of non-magnetic stainless steel.

The measurements in this comparison were carried out from April 2005 to December 2005. The CENAM contributed the travelling standards and supplied their reference values.

The density, the magnetic susceptibility, permanent magnetization, and conventional mass of all travelling standards except the density of the 200 mg were determined. A visual comparison of the surface roughness against roughness standards proved that the travelling standards complied with the accuracy class of OIML E [1,2].2

The comparison protocol as well as the volume data were included in the travel container in which the standards were transported.

The SIM identification for this comparison is: SIM.7.31a (1 kg) and SIM.7.31b (2 kg, 200 g, 50 g, 1 g y 200 mg).

2. AIM OF THE PROGRAM

The aim of this comparison is to give confidence of the technical capacity of the SIM members and work in the mutual recognition agreements within the SIM and at the international level. On the other hand this comparison gives objective evidence about the technical competence of the laboratories, and it assists in identifying opportunities to improve the metrological assurance systems.

One of the problems in organizing comparisons, in which different countries are involved, is that each of them has different necessities and different capabilities; this can be seen in the wide range of uncertainty reported by the participants.

3. PARTICIPANTS

Table 1 shows the seven participating laboratories of the SIM sub-regions.

26

Laboratory Acronym Country SIM Sub region

Centro Nacional de Metrología

CENAM/ Pilot

laboratory

México

NORAMET

Bureau of Standards, Jamaica

BSJ

Jamaica

CARIMET

Laboratorio Costarricense de Metrología

LACOMET

Costa Rica

CAMET

Instituto Boliviano de Metrología

IBMETRO

Bolivia

ANDIMET

Centro de Estudios, Medición y Certificación de Calidad

CESMEC

Chile

SURAMET

Instituto Nacional de Defensa de la Competencia y de la Protección de la Propiedad Intelectual.

INDECOPI

Peru

ANDIMET

Instituto Nacional de Tecnología,

Normalización y Metrología

INTN

Paraguay

SURAMET

4. DESIGN OF THE PROGRAM AND TIME SCHEDULE

The program was designed according to the guidelines for CIPM (Comité International des Poids et Measures) key comparisons [3] and were used six travelling standards of 2 kg, 1 kg, 200 g, 50 g, 1 g and 200 mg were used. These standards comply with the requirements of class E of the 2

International Recommendation OIML R111 [1,2]. The travelling standards were circulated in only one petal of SIM sub-regions. As pilot laboratory, CENAM determined the conventional mass of the travelling standards at the beginning and the end of the comparison.

The transportation of the travelling standards to the next participant was done by hand in order to avoid any contamination or damage.

Table 2 shows the measurements scheduled and the starting dates of each laboratory.

Table 1: Participating Laboratories

INSTITUTE PERIOD OF MEASUREMENTSCENAM April-May 2005

BSJ May 2005 LACOMET June 2005 IBMETRO August 2005 INDECOPI September 2005

INTN October 2005 CESMEC November 2005 CENAM

December 2005-January 2006

Table 2:- Sequence of the measurements

Figure 1 shows the transportation sequence and measurements of the travelling standards.

Figure 1.

CENAM

LACOMET IBMETRO

INTN

INDECOPI BSJ

CESMEC

5. REPORTING BY PARTICIPANT

The measurement results were sent to the pilot laboratory in a final report where a list of the equipment used as balances and environmental conditions were included, besides the reference standard used in order to see the traceability on each laboratory.

6. STABILITY OF THE TRAVELLING STANDARDS

The pilot laboratory (CENAM) monitored the stability of the travelling standards during a period of 2 months before beginning of the laboratory measurements. No significant instability has been found, so that, the conventional mass values of the traveling standards were stable during this period.

The travelling standards were circulated among six participating laboratories without any incident that required any return to the pilot laboratory to re measure the travelling standards.

27

7. REFERENCE VALUES

7.1 The reference values for this comparison were determined for the CENAM with an expanded uncertainty calculated as is described in 7.6.1, 7.6.2 and 7.3.

7.2 Before circulating the travelling standards of 2 kg, 1 kg, 200 g, 50 g and 1 g their volumes were determined at the CENAM density laboratory. The assumed density of the 200

-3mg weight was 7 950 kg m as given by the manufacturer.

7.3 The expanded uncertainties of the reference values were obtained, according to GUM-1995 [4], as the combined standard uncertainties multiplied by the coverage factor k = 2. The expanded uncertainty corresponds to a coverage probability of approximately 95%. The uncertainty was formed from the uncertainty of measurement of the reference standard used, the weighing process and the air buoyancy correction. The uncertainty component due to long-term changes was negligible.

7.4 Table 3 gives the mass changes m between the two re-calibrations by the pilot laboratory and the resulting drift uncertainties calculated by means of equation c):

Table 3. Changes in mass of the travelling standards

Nominal Value

Reference uncertainty

(k=2)

|Dm| Drift uncertainty

(k=2) 2 kg 0,08 mg 0,05 mg 0,03 mg 1 kg 0,03 mg 0,00 mg 0,00 mg

200 g

0,012 mg

0,020 mg 0,012 mg

50 g

0,006 mg

0,002 mg

0,001 mg

1 g

0,002 mg

0,000 mg

0,000 mg

200 mg

0,001

2 mg 0,000 4 mg

0,000 2 mg

7.5 The instability of the travelling standards was taken into account in the calculation of the reference values and was included in the E [5] n

value as an additional uncertainty component.

7.6 Therefore, the conventional mass values of the participants have to be linked to a CENAM's reference standards using the rules:

7.6.1 If two consecutive determinations of reference values are within the limits of the reference uncertainty, their mean

value is used by all participants because we do not know when the value changed.

7.6.2 If two reference values m and m , were 1 2

at times t and t , differ significantly, a 1 2

linear drift is assumed and for a participant i, measuring at time t the i

mass m was interpolated using the PL,i

following equation.

( )12

11,2,1,,

tt

ttmmmm i

PLPLPLiPL-

--+= a)

8. RESULTS OF PARTICIPATING LABORATORIES

8.1 The results were sent directly to the pilot laboratory (CENAM).

8.2 The results of the measurements are shown in the tabular form, see table 4 to table 9 and as a graphical representation, see 1 to 6. The E value [4] is obtained from the following n

expression.

222

dPLA

PLAn

UUU

mmE

++

-= b)

m and U are the conventional mass value PL PL

and uncertainty associated with the pilot laboratory are while m and U are the A A

conventional mass value and the uncertainty associated with the part icipating laboratories.

A drift uncertainty U for the mass instability d

of the travelling standards is taken into account with the following equation:

2

1,2,

32 ÷÷ø

öççè

æ -= PLPL

d

mmkU

c)

8.3 In the tables from 10 to 15 are included the E values for all the travelling standards and n

for all the participants, including the pilot laboratory. The following rules were considered.

8.4 Participant A and pilot laboratory PL.

The value E is calculated according to n

equation b):the measurements are considered as uncorrelated, in this case the denominator of (b) the equation is:

28

( )÷÷

ø

ö

çç

è

æ -++

3

2

1,2,22 PLPL

PLA

mmUU d)

8.5 Participant A and B from the same petal.The value E is calculated according to n

equation b):the measurements are considered as uncorrelated in this case the denominator from the equation b) is:

( )÷÷

ø

ö

çç

è

æ -+++

3

2

1,2,222 PLPL

PLBA

mmUUU e)

Table 4:- Results for the 2 kg standard

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM - 0,20 0,08 BSJ - 0,225 - 0,18 2,38

LACOMET

- 0,225

- 0,24

1,46

IBMETRO

- 0,225

- 0,90

3,00

INDECOPI

- 0,225

+ 0,50

1,00 INTN

- 0,225

+ 0,20

3,00

CESMEC

- 0,225

- 0,20

1,00 CENAM

- 0,25

0,08

Table 5:- Results for the 1 kg standard

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM - 0,16 0,03 BSJ - 0,16 - 0,09 1,28

LACOMET - 0,16 - 0,214 0,046 IBMETRO

- 0,16

- 0,128

0,154

INDECOPI

- 0,16

- 0,20

0,26

INTN

- 0,16

- 0,1

1,6

CESMEC

- 0,16

- 0,14

0,50

CENAM

- 0,16

0,03

Table 6:- Results for the 200 g standard

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM - 0,365 0,012 BSJ - 0,363 - 0,37 0,24

LACOMET - 0,361 - 0,367 9 0,009 6 IBMETRO - 0,356 - 0,381 0,034 INDECOPI

- 0,354

- 0,36

0,05

INTN

- 0,352

- 0,30

0,30

CESMEC

- 0,349

- 0,32

0.10

CENAM

- 0,345

0.012

Tablet 7:- Results for the 50 g standard

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM - 0,061 0,006 BSJ - 0,060 - 0,08 0,10

LACOMET - 0,060 - 0,063 8 0,014 2 IBMETRO - 0,060 - 0,052 0,016 INDECOPI - 0,060 - 0,062 0,016

INTN - 0,060 - 0,08 0,10 CESMEC - 0,060 - 0,065 0,030 CENAM

- 0,059

0,006

Table 8:- Results for the 1 g standard

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM + 0,028 0,002 BSJ + 0,028 + 0,030 0,040

LACOMET

+ 0,028 + 0,025 9 0,001 5

IBMETRO + 0,028 + 0,026 4 0,003 2 INDECOP

I

+ 0,028

+ 0,027

0,005

INTN

+ 0,028

+ 0,027

0,030

CESMEC

+ 0,028

+ 0,027

0,010 CENAM

+ 0,028

0,002

Table 9:- Results of the standard of 200 mg

Laboratory Reference value

mPL-mn (mg)

Laboratory value

ml-mn (mg)

Laboratory uncertainty

Ul (mg)

CENAM + 0,000 7 0,001 2 BSJ + 0,000 55 - 0,002 0,020

LACOMET + 0,000 55 + 0,000 08 0,000 54 IBMETRO + 0,000 55 - 0,004 4 0,002 2 INDECOPI

+ 0,000 55

+ 0,000

9

0,003

2

INTN

+ 0,000 55

+ 0,003

0,020

CESMEC

+ 0,000 55

+ 0,001

0,006

CENAM

+ 0,000 4

0,001

2

Where:

m is the nominal value of the travelling standardsn

m is the laboratory value of the travelling l

standardsm is the reference value of the travelling PL

standards

29

9. CONCLUSIONS

Of the 36 measurements results for the mass of the travelling standards, were used for calculating the respective E value between participants, see n

tables 10 to 15 of which one are greater than one respect to pilot laboratory and two are greater than one between them, these values were calculated using the d) and e) formulas. The degree of agreement among the participants seen to be excellent, in other words, the mass measurements carried out among SIM region members do not differ significantly.

The uncertainties of each participant are plotted in graphical representation, see graphics 1 to 6 using the d) formula.

The names of the participating laboratories were included in the report as an agreement between them.

ACKNOWLEDGMENT

Some of the participant institutions wish to acknowledge to their colleagues who they carried out the mass measurements:

Leticia Luján Solís CENAMRaúl Hernández CESMECSheldon Walker BSJOscar Andrey Herrera Sancho LACOMET

REFERENCES

[1] OIML R111, Weights of classes E , E , F , 1 2 1

F , M , M , M , 1994.2 1 2 3

[2] Norma Oficial Mexicana NOM-038-SCFI-2000, Pesa de clase de exactitud E , E , 1 2

F , F , M , M , M .1 2 1 2 3

[3] Guidelines for CIPM key comparisons http://www.bipm.fr/utils/en/pdf/guidelines.pdf

[4] Guide to the Expression of Uncertainty in Measurement, International Organization for Standardization, Geneva, Switzerland, 1995.

[5] W. Wöger, “Remarks on the E -criterion n

Used in Measurement Comparison, Internationale Zusammenarbeit.PTB-Metteilungen 1999. Pages 24-27.

30

APPENDIX A – GRAPHICS

Graphic 1: The difference between the laboratory value and the reference value: 2 kg

2 kg

-6.000

-4.000

-2.000

0.000

2.000

4.000

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

Graphic 2: The difference between the laboratory value and the reference value: 1 kg

1 kg

-0.600

-0.200

0.200

0.600

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

Graphic 3: The difference between the laboratory value and the reference value: 200 g

200 g

-0.150

-0.100

-0.050

0.000

0.050

0.100

0.150

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

Graphic 4: The difference between the laboratory value and the reference value: 50 g

50 g

-0.150

-0.100

-0.050

0.000

0.050

0.100

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

Graphic 6: The difference between the laboratory value and the reference value: 200 mg

200 mg

-0.0100

-0.0050

0.0000

0.0050

0.0100

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

Graphic 5: The difference between the laboratory value and the reference value: 1g

1 g

-0.015

-0.010

-0.005

0.000

0.005

0.010

0.015

BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

Laboratory

31

APPENDIX B – En VALUES

Table 10: The E value for 2 kgn

2 kg CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM 0.02 -0.01 -0.23 0.72 0.14 0.02

BSJ -0.02 -0.02 -0.19 0.26 0.10 -0.01

LACOMET 0.01 0.02 -0.20 0.42 0.13 0.02

IBMETRO 0.23 0.19 0.20 0.44 0.26 0.22

INDECOPI -0.72 -0.26 -0.42 -0.44 -0.09 -0.49

INTN -0.14 -0.10 -0.13 -0.26 0.09 -0.13

CESMEC -0.02 0.01 -0.02 -0.22 0.49 0.13

Table 11: The E value for 1 kgn

1 kg CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM 0.05 -0.98 0.20 -0.15 0.04 0.04

BSJ -0.05 -0.10 -0.03 -0.08 0.00 -0.04

LACOMET 0.98 0.10 0.53 0.05 0.07 0.15

IBMETRO -0.20 0.03 -0.53 -0.24 0.02 -0.02

INDECOPI 0.15 0.08 -0.05 0.24 0.06 0.11

INTN -0.04 0.00 -0.07 -0.02 -0.06 -0.02

CESMEC -0.04 0.04 -0.15 0.02 -0.11 0.02

Table 12: The E value for 200 gn

200 g CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM -0.03 -0.38 -0.66 -0.12 0.17 0.29

BSJ 0.03 0.01 -0.05 0.04 0.18 0.19

LACOMET 0.38 -0.01 -0.33 0.15 0.23 0.47

IBMETRO 0.66 0.05 0.33 0.33 0.27 0.57

INDECOPI 0.12 -0.04 -0.15 -0.34 0.20 0.35

INTN -0.17 -0.18 -0.23 -0.27 -0.20 -0.06

CESMEC -0.29 -0.19 -0.47 -0.57 -0.35 0.06

Table 13: The E value for 50 gn

50 g CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM -0.20 -0.25 0.47 -0.12 -0.20 -0.16

BSJ 0.20 0.16 0.28 0.18 0.00 0.14

LACOMET 0.25 -0.16 0.53 0.08 -0.16 -0.04

IBMETRO -0.47 -0.28 -0.53 -0.43 -0.28 -0.38

INDECOPI 0.12 -0.18 -0.08 0.43 -0.18 -0.09

INTN 0.20 0.00 0.16 0.28 0.18 0.14

CESMEC 0.16 -0.14 0.04 0.38 0.09 -0.14

32

Table 14: The E value for 1 gn

1 g CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM 0.04 -0.94 -0.48 -0.23 -0.01 -0.12

BSJ -0.04 -0.10 -0.09 -0.07 -0.03 -0.07

LACOMET 0.94 0.10 0.13 0.21 0.01 0.11

IBMETRO 0.48 0.09 -0.13 0.10 0.01 0.06

INDECOPI 0.23 0.07 -0.21 -0.10 0.00 0.00

INTN 0.01 0.03 -0.01 -0.01 0.00 0.00

CESMEC 0.12 0.07 -0.11 -0.06 0.00 0.00

Table 15: The E value for 200 mgn

200 mg CENAM BSJ LACOMET IBMETRO INDECOPI INTN CESMEC

CENAM -0.13 -0.34 -1.96 0.11 0.12 0.08

BSJ 0.13 0.10 -0.12 0.14 0.18 0.14

LACOMET 0.34 -0.10 -1.75 0.24 0.15 0.15

IBMETRO 1.96 0.12 1.75 1.30 0.37 0.83

INDECOPI -0.11 -0.14 -0.24 -1.30 0.10 0.01

INTN -0.12 -0.18 -0.15 -0.37 -0.10 -0.10

CESMEC -0.08 -0.14 -0.15 -0.83 -0.01 0.10

33

XII Asamblea General del SIM

En Río de Janeiro, Brasil, los días 16 y 17 de septiembre de 2006 se celebró la XII Asamblea General del Sistema Interamericano de Metrología con la participación de países miembros, observadores y diversos organismos e instituciones invitados. Fueron presentados los informes de la Presidenta del SIM -noviembre 2005 - septiembre 2006-, del Consejero Técnico Permanente, del Secretario Ejecutivo, del Comité Técnico, del Representante del SIM ante el JCRB, del Comité de Desarrollo Profesional, del representante del SIM ante el NCSLi, así como de las sub-regiones del SIM. El espíritu general que permeó en el ambiente fue de unidad y de renovación de esfuerzos para apoyar el desarrollo de las economías representativas del SIM.

Capacitación

· Curso de metrología legalEn Bogotá, República de Colombia, del 5 al 7 de diciembre de 2005, coordinado por la División de Metrología de la Superintendencia de Industria y Comercio, de Colombia y el Centro Nacional de Metrología, México.

· Taller regional sobre fuerza Los días 23 y 24 de marzo de 2006, con los INM de la región andina, en la ciudad de Santiago, República de Chile.

· Seminarios sobre tiempo y frecuencia, mediciones de gas natural, metrología química y metrología legalFueron promovidos por la sub región SURAMET del SIM en el periodo 2005/2006 con sedes en Asunción, Paraguay; Buenos Aires, Argentina; Montevideo, Uruguay y Río de Janeiro, Brasil, respectivamente. Participaron connotados especialistas de otros institutos del SIM y de otras regiones.

XII SIM General Assembly

Held in Rio de Janeiro, Brazil, on September 16 - 17, 2006, with the participation of SIM members, observers and several invited organizations. Reports were presented from the SIM President -November 2005 - September 2006-, the Permanent Technical Advisor, the Executive Secretariat, the Technical Committee the representative of SIM to the JCRB, the Professional Development Committee, the SIM representative to the NCSLi, and those of the SIM sub-regions. The general environment was one of unity and renewal of efforts to support the development of the SIM economies.

Training

· Legal metrology course Held in Bogotá, Republic de Colombia, December 5 – 7, 2005, coordinated by the Division of Metrology of the Superintendent for Industry and Commerce, Colombia, and CENAM.

· Regional workshop on forceHeld on March 23 – 24, 2006, in Santiago, Republic of Chile, with the participation of the NMIs of the Andean region.

· Seminars on time and frequency, natural gas measurements, chemical metrology and legal metrology

Sponsored by the SURAMET sub region in the period 2005/2006, and held respectively in Asunción, Paraguay; Buenos Aires, Argentina; Montevideo, Uruguay and Rio de Janeiro, Brazil. Specialists from SIM NMIs and other regions participated.

NOTI-SIM