News of the Year

Scientific Divisions

Quantum voltmeter to measure AC voltages for industry

Within the scope of a technology transfer project (MNPQ project) which is supported by the Federal Ministry of Economics and Technology and involves PTB and two partners from industry, a Josephson measuring system for DC and AC voltages – an AC quantum voltmeter – has been developed for use in industrial calibration laboratories. With this new system, the considerable advantages of standards which are based on electrical quantum effects will also become available to industrial laboratories: very low measurement uncertainties without tedious recalibrations improve performance while becoming more economical. The system is based on Josephson arrays, which are manufactured at PTB, and is designed for peak voltages of up to ± 10 V and frequencies of up to 10 kHz. With a prototype, AC voltages from 10 Hz to 4 kHz have already been measured at PTB, whereby uncertainties of a few μV/V within a measuring time of one minute were attained. This makes the new AC quantum voltmeter approximately 20 times more accurate than conventional calibrators and 60 times faster than the measurement procedures with thermal converters used to date. In addition, the AC quantum voltmeter can also calibrate commercial DC voltage standards (DC references and DC voltmeters).

The new AC quantum voltmeter is now being optimized by means of on-site tests at an accredited laboratory. The main objective is to reach a relative uncertainty of 2.5 μV/V at 1 kHz. The system will be developed in a modular approach which will an future extension of the system to a universal «quantum calibrator» for voltage, resistance and current standards.

Metrology for electrochemical energy storage systems: Determination of the state of charge and the state of health of lithium-ion batteries

Presently, the results of the EIS measurements, which are obtained with different measuring instruments, are not really suited for quality assurance as they do not provide any information on the uncertainty of the parameters measured, and as the results may depend on the device. Secured information on the assignment of the parameters determined from the impedance spectra to the chemical processes in the battery during its use and storage under different environmental conditions are lacking. The two temperature-controlled EIS reference measuring set-ups realized now allow essential parameters for the SOC and SOH to be identified from the impedance spectra and to be measured in such a way that they are traceable to the SI.

With the aid of a reference impedance developed in cooperation with the “AC/DC Transfer, Impedance” Working Group, the measuring set-ups were characterized independent of the device. The establishment of further dynamic reference impedances with varying resistances and capacitances, which cover the relevant mHz to kHz measurement range, is planned. This allows electrochemical impedance spectrometers to be calibrated for the first time in this measurement range.

The results of the EIS reference measurements carried out on lithium-ion battery cells can be transferred to the quality assurance of the results of measurements carried out on other energy stores and converters such as, e.g., fuel cells. It is planned to extend the reference measurement procedure in future for the investigation of battery cells and modules up to a capacity of 150 Ah.

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Roadmap towards the redefinition of the kilogram

In connection with the discussions about the revision of the International System of Units (SI), a new recommendation (CCM Recommendation G 1 (2013) “On a new definition of the kilogram”) was adopted at this year’s session of the Consultative Committee for Mass and Related Quantities (CCM). This recommendation specifies previous CCM Recommendations and formulates four fundamental conditions which the CCM considers indispensable for the kilogram to be re-defined:

R1: At least three experiments, among these wattbalance experiments and the Avogadro experiment, provide consistent values for Planck’s constant h with relative standard uncertainties of no more than 5 ∙ 10^–8.
R2: At least one of these results exhibits a relative standard uncertainty of no more than 2 ∙ 10^–8.
R3: The BIPM prototypes, the “BIPM ensemble of reference mass standards”, and the mass standards of the watt-balance experiments and of the Avogadro experiment, respectively, have been compared with the International Prototype of the Kilogram as directly as possible.
R4: The procedures for the future realization and dissemination of the kilogram, as described in the relevant “mise en pratique”, have been successfully tested and validated in accordance with the principles of the CIPM MRA.

This CCM Recommendation has meanwhile been confirmed by the Comité International des Poids et Mesures (CIPM).

Micro gear measurement standard

Within the scope of an AiF project, PTB has developed a novel micro gear measurement standard in cooperation with partners from industry. This standard allows the suitability of coordinate measuring machines with tactile and/or optical sensors and the suitability of dimensionally measuring computer tomographs (CTs) for the measurement of micro gears to be checked and compared.

Micro gears and smallest-sized gears with transverse modules between 1 μm and 1 mm have become an indispensable part of modern manufacturing. The applications, for example in micro systems technology manufacturing or in microrobotics, often require gears with a minimum of material, but with a high degree of precision and efficiency. Due to their size and geometry, micro gears present, however, particularly high challenges for metrology. In addition to tactile metrology, which is usually applied to gears, other measurement principles (e.g. optical or tomographic principles) are increasingly taken into account. Suitable measurement standards which ensure the traceability of these measurements and, thus, allow their quality to be assessed by the determination of a task-specific measurement uncertainty have so far, however, been lacking.

PTB‘s new micro gear measurement standard embodies four different gear quantities with transverse modules of 0.1/0.2/0.5/1.0 mm. On the standard, both profile and helix measurements can be performed and the diametrical dimension over balls can be determined. All parameters were calibrated on a micro coordinate measuring machine with measurement uncertainties U(k = 2) of less than 1 μm. The universal suitability of the standard for tactile and optical sensors as well as for dimensional computer tomography could be demonstrated by comparison measurements which were carried out on five different measuring instruments.

Symmetry breakings in ion Coulomb crystals

Scientists of the Excellence Cluster QUEST have used laser-cooled ions in so-called “ion Coulomb crystals” in order to generate symmetry breakings in a controlled manner. Thereby, they were able to observe the occurrence of defects. Realizing these so-called “topographical defects” experimentally within a well-controlled system opens up new possibilities when it comes to investigating quantum phase transitions and looking in detail into the nonequilibrium dynamics of complex systems. Among other things, conclusions can be drawn as to the development of the universe shortly after the big bang. The results were published in the scientific journal “Nature Communications”.

Within the scope of an international cooperation with colleagues from the Los Alamos National Lab (USA), from the University of Ulm (Germany) and from the Hebrew University (Israel), researchers have now, for the first time, succeeded in demonstrating topological defects in an atomic-optical experiment in the laboratory. Topological defects are errors in the spatial structure which are caused by the breaking of the symmetry when particles of a system cannot communicate with each other. They form during a phase transition and present themselves as non-matching areas. The experimental challenge for the researchers consisted in being able to control a complex multi-particle system and to induce an intentional change in the external conditions to obtain the symmetry breaking. This was achieved by means of ytterbium ions which were trapped in so-called “radio-frequency ion traps” in ultra-high vacuum and were cooled down to a few millikelvin with the aid of laser light. The trapped, positively charged particles repel each other inside the trap and, at such ultra-low temperatures, take on a crystalline structure (Fig. a–c).

If the parameters of the trap enclosure are varied faster than the speed of sound in the crystal, then topological defects occur (Fig. d–e) while the ions are seeking a new equilibrium condition in the crystal. The stability of these effects was investigated and optimized by means of numerical simulations. This provides an ideal system to investigate the physical properties of symmetry-breaking transitions with the highest sensitivity.

The new system now demonstrated will soon allow further experiments on phase transitions in classical systems and in the quantum universe as well as tests in the field of nonlinear physics (e.g. solitons) to be performed in a well-controlled comparative system.

A medical CT scanner for dosimetry

In medical X-ray diagnostics, computed tomography (CT) is a method which has established itself in hospitals and medical practices worldwide. Due to the rapid technological development of CT devices with constantly increasing scanning widths, the well-proven dose concept for computed tomography can no longer be used consistently. Meanwhile, international working groups have proposed a series of different modern CT dose concepts. PTB is of the opinion that a uniform CT dose concept that is valid worldwide is indispensable for continuing to ensure the comparability of dose measurands.

Since PTB is not only responsible for realizing and disseminating the units of the quantities used in CT dosimetry but also for issuing type approvals for CT dosimeters for radiodiagnostics, and since it cooperates furthermore in the respective national and international standardization committees, there is an urgent need for action in this field. For this reason, PTB has purchased its own medical CT scanner for CT dosimetry. This CT will first be characterized as a reference measuring facility for CT dosimetry. The reference measuring facility will then be used to test the proposed dose concepts and the novel detectors used in CT dosimetry – also within the scope of type tests.

Quantum metrology with SQUIDs

PTB has taken on a worldwide leading role in the development of SQUIDs for precision measurements. Within the scope of two international cooperation projects, SQUID sensors developed and fabricated at PTB have now been successfully used in challenging quantum physics experiments. One of these projects was a so-called “Bell experiment” of Anton Zeilinger’s group from the Austrian Academy of Sciences (Österreichische Akademie der Wissenschaften). To detect quantum-mechanically entangled photons with high efficiency (and a sufficient number of them), superconducting transition edge sensor microcalorimeters of the Quantum Detector Group of the National Institute of Standards and Technology (NIST, USA) and PTB’s SQUID current sensors were used as single-photon detectors. The configuration of the TES/SQUID detector modules used and their tests were performed at PTB. These experiments have allowed the most complete detection of the quantum-mechanical entanglement of photons so far. This makes photons the first quantum particles for which all the so-called “loopholes” in Bell experiments have been closed.

The second experiment is part of a close cooperation which has existed since the mid-1990s between PTB’s Cryosensors Group and John Saunders’ group at the Royal Holloway, University of London, in which particularly sensitive NMR spectrometers are being developed. The PTB SQUIDs used have now enabled – with unprecedented sensitivity – NMR experiments on the quantum fluid helium-3 at ultra-low temperatures. Among other things, the super-fluid properties of extremely thin helium-3 liquid lamellas in cavities under pressure and down to temperatures well below 1 mK were investigated. The measurements showed that the relatively complex phase pattern of helium-3 is strongly modified by the “confinement” and by the properties of its surface towards its environment.

Nuclear spin precession measurements for fundamental physics research

In the past few years, precision measurements of the nuclear spin precession of noble gases have moved into the focus of fundamental research in physics as they may help to clarify current questions of cosmology and particle physics. For these investigations, PTB’s magnetically shielded room BMSR-2 offers an extremely low-noise environment in which the coherent nuclear spin precession of noble gases in a weak magnetic field can be maintained for a long time. A highly sensitive magnetic measurement technology based on SQUIDs then enables a very precise determination of the Larmor frequency of the spin precession and, thus, the Zeeman energy of the two nuclear levels. If an additional, non-magnetic interaction acts on the nuclear spin, this should lead to a corresponding variation of the precession frequency.

Such an interaction could be mediated by the axion – a hypothetical particle postulated by theories. The axion is also regarded as a possible candidate for the dark matter which is assumed to make up more than 75 % of all matter in the universe. In the past few years, PTB Departments 8.1 and 8.2 have carried out and analyzed experiments in cooperation with the Johannes Gutenberg University, Mainz. The result of these experiments was that the previous upper bounds of the mass and coupling strength of the axion had to be considerably reduced.

Other projects are dealing with the search for the electric dipole moments of the neutron and of the xenon nucleus. The existence of these electric dipole moments would imply a fundamental symmetry violation which could explain the dominance of matter over antimatter in our world. The respective experiments are being carried out in cooperation with the Paul Scherrer Institute (PSI) in Villigen (Switzerland) and with the Technical University of Munich. When the magnetic shielding at the neutron sources of the two research institutes was constructed and redesigned, the homogeneity of the residual magnetic field could be improved by one order of magnitude through the participation of PTB. In the shielded room of TU Munich, with only 2 layers of Mu-metal, a residual magnetic field was obtained whose homogeneity even approximates the record values of BMSR-2. The experiments to search for the considerably weaker dipole moment of the xenon nucleus are also performed at PTB’s BMSR-2. The polarization of the noble gases required for this purpose (¹²⁹Xe and ³He) is realized at PTB’s Department 8.1.

Stability of the superfluidity in mixtures of Bose-Einstein condensates

Like ultra-cold helium, Bose-Einstein-condensed atoms also exhibit flowing without friction: superfluidity. Like superconductivity, superfluidity is a macroscopic quantum phenomenon which can only be understood and described within the framework of quantum mechanics. It is used in science and technology as well as in metrology, e.g. for high-precision measurements of magnetic fields with the aid of so-called SQUIDs or for voltage measurements on the basis of the Josephson effect.

For this reason, the superfluidity of atomic Bose- Einstein condensates has been investigated recently, in particular also with respect to possible applications for precision measurements. In a large number of new experiments, condensed atoms are trapped in a ring-shaped optical trap. Then, a superflow is excited by a suitable laser pulse, i.e. the atoms in the optical trap are caused to rotate. This is also called “excitation of a vortex”. Due to the quantum nature of the condensate, the angular momentum connected with a vortex is quantized and can only be changed in quantized steps.

In such an experiment, which was performed by a group from Cambridge University [1], it was found out that the superflow of a mixture of rubidium atoms in different spin states is – depending on the mixing ratio – stable above a critical threshold (i.e. for a long time, the atomic condensate rotates without friction), but rotation stops rather abruptly below this threshold. Thereby, the quantized loss of angular momentum in the vortex was directly observed.

Within the scope of a project of the working group “Theory of Interacting Quantum Systems”, and in cooperation with physicists from the Ukraine and funded by the German Academic Exchange Service (Deutscher Akademischer Austauschdienst, DAAD), a proposal [2] was made as to how this behavior can be understood. To this end, the experiment [1] was simulated as closely as possible within the scope of a mean field approximation on the computer. This allows the behavior of the atomic condensate to be exactly “observed” on time and length scales which are not directly accessible to the experiment, to find out how the atomic liquid exactly behaves in the decay.

The simulation starts with a homogeneous distribution of the atoms on two spin components – here designated with “+” and “0” – which rotate with three angular momentum units. (A “-” component which is theoretically possible for rubidium is filtered out both in the experiment and in the simulation.) The figure shows the density of the condensate of the spin component “+” after approx. 13 time units in a color-coded presentation. The ring, in which the condensate is “locked” and rotating, is clearly visible. At this moment, the density is, however, already rather inhomogeneous and there is even almost a hole (dark blue area) in the ring-shaped condensate. This density minimum in one component is filled with atoms of the other component. Such a local phase separation into single spin components occurs as a function of the initial mixing of spin components of the atoms. At this point in time, the original vortex has already separated into several vortices whose rotation centres are characterized by the white + marks in the figure. After that, one of the vortices that have developed succeeds in escaping through the density minimum and, thereby, the superfluid gas loses one angular momentum unit. In further steps, the atomic liquid then completely loses its vorticity. The supplemental material of the original publication [1] includes a short movie which shows the decay of the superfluid vortex in some detail.

It may be expected that spintronics and atomtronics, which have been investigated in our simulation, will in the future play a similarly important role in technology and metrology to electronics today.

[1] S. Battie, S. Moulder, R. J. Fletcher, Z. Hadzibabic, Phys. Rev. Lett. 110 (2013) 025301.
[2] A. I. Yakimenko, K. O. Isaeva, S. I. Vilchinskii, M. Weyrauch, Phys. Rev. A88 (2013) 051602(R)

Advisory Board

The 64^th meeting of the Kuratorium (Advisory Board) of PTB

The annual meeting of the Kuratorium of PTB was held this year on 25 and 26 April in Braunschweig. The members of the Kuratorium and guests were welcomed by the President of PTB, Prof. Dr. Joachim Ullrich. Next, the members of the Kuratorium were given the opportunity to gain an insight into ongoing research and PTB service projects at selected stations. The choice of subjects thereby ranged from fundamental research to optical clocks, from antenna characterization in the gigahertz range to the testing of compression-proof housing in Explosion Protection. Following this, an open colloquium was held in PTB’s auditorium, at which three young PTB scientists reported on their research work. Christine Brauckmann was first with her speech on the development of primary measuring methods for “priority hazardous materials” of the EU Water Framework Directive, followed by Dr. Tanja Mehlstäubler with a topic from fundamental research, “Crystal defects in laser-cooled ion crystals – from cosmology to solid state physics” and finally, Dr. Katy Klauenberg with her speech on a novel statistical method for analyzing immunoassays. The members of the Kuratorium used the remaining time on the first day of the meeting for intensive talks in the technical divisions.

The meeting of the Kuratorium on 26 April was opened by the President of the Kuratorium, Dr. Sven Halldorn. In his subsequent speech, he addressed the issues of the current economic situation in Germany, the innovation policy of the German federal government, the support programmes of the BMWi, the European research programme Horizont 2020 (Horizon 2020), the quality infrastructure in reference to metrology, accreditation and standardization as well as the framework conditions for the departmental research in connection with the “Scientific Freedom Initiative”. He pointed out that PTB has an important function – that of increasing the acceptance of technology in the economy and by the consumer. The basic concept here is to have accurate and traceable measurements that are an essential basis for reliable and quality-assured production processes. Technical progress requires continually expanding measurement capabilities, which is why in spite of enormous efforts towards consolidation of public budgets, research, development and innovation have a high priority for the German federal government.

Following this, Prof. Ullrich gave an overview of the most important work performed by PTB in the past year. In the first part of his speech, he went into the state of and the progress made in the further development of the International System of Units (SI). In the focus here were the Avogadro Project, the definition of the ampere with single-electron circuits as well as the research on optical atomic clocks. Then he presented highlights from the service fields such as, e.g., the planned extension of the force scale to 30 MN or the use of profile scanners for the investigation of microstructures. Stock was taken of the European metrology research programme EMRP, and the future prospects of the subsequent programme EMPIR followed. At the conclusion of his speech, he mentioned the new mentoring concept for doctoral candidates, the measures for the compatibility of career and family (work-life balance), and reported on the training programmes at PTB.

Presidential Board

Presentation of the EPS Historic Site Award to PTB

On 8 October 2013, PTB in Berlin was presented with the Historic Site Award of the European Physical Society (EPS). This award honours sites that were and still are of great importance in the development of physics. With PTB’s nomination, the groundbreaking scientific and technical achievements made by Hermann von Helmholtz, Walter Nernst, Willy Wien and others at the – then – Physikalisch- Technische Reichsanstalt (Imperial Physical Technical Institute – PTR) at the start of the 20th century were honoured.

The speakers at the ceremony marking the presentation of the Historic Site Award at PTB Berlin on 8.10.2013 (from left to right): Prof. Hans Koch (Head of PTB’s Berlin Institute), Prof. Wolfgang Ketterle (Nobel Prize winner 2001 and PTB Kuratorium member), Cornelia Quennet-Thielen (State Secretary of the BMBF), Prof. John Dudley (EPS President), Prof. Joachim Ullrich (PTB President), Prof. Johanna Stachel (DPG President), Anne Ruth Herkes (State Secretary of the BMWi)

Around 100 invited guests from the fields of industry and science came to this ceremony, including the President of the Deutsche Physikalische Gesellschaft (DPG), Prof. Johanna Stachel, the President of PTB’s Kuratorium (Advisory Board), Dr. Sven Halldorn, and Ruprecht von Siemens, the great-grandson of the founder of the Siemens company and also of Hermann von Helmholtz. The musical accompaniment to this event was provided by young prizewinners of Jugend musiziert – a German project supporting young musicians – from Berlin.

The State Secretaries Anne Ruth Herkes from the German Federal Ministry of Economics and Technology (BMWi) and Cornelia Quennet-Thielen from the German Ministry of Education and Research (BMBF) delivered welcoming speeches in which they underlined the importance of the historic scientific achievements for the economy and science.

The award was actually presented by the President of the EPS, Prof. John Dudley.

The scientific highlights of the ceremony were formed by the talks given by the Nobel Prize winner and new member of PTB’s Kuratorium, Prof. Wolfgang Ketterle, on quantum matter at absolute zero temperature, and by Prof. Hans Koch on the discovery of the quantum nature of light.

100 years of Helmholtz-Fonds e. V.

When PTB’s preceding institute, the PTR, was a quarter of a century old, renowned scientists of the PTR Kuratorium decided to establish a fund for promoting and supporting the PTR. The Helmholtz- Fonds e. V. (Helmholtz Fund), named after the first PTR president, has since then been extremely supportive of metrological research and development. In 2013, the Helmholtz-Fonds celebrated its 100th anniversary with a ceremonial colloquium on 20 September 2013 in the PTB auditorium in Braunschweig.

After the short welcoming speech by Dr. Sven Halldorn, Head of the “Technology Policy” Department at the BMWi, Mr. Dipl.-Ing. Ruprecht von Siemens (former treasurer of the Helmholtz-Fonds) and Prof. Dr. Ernst O. Göbel (former PTB president) spoke about the history and the importance of the Helmholtz-Fonds. Next, Prof. Dr. Günter Werth, Dr. Fritz Riehle and Prof. Dr. Thomas Klar – three scientists whose work has been distinguished with the Helmholtz Prize in the past – each gave a brief speech on the field of their award-winning work. Following this colloquium, there was a reception in the foyer of the auditorium.

Kindergarten opens

On Thursday, 6 June 2013 the new rooms of PTB’s kindergarten were officially opened. The 25 children who have attended the newly founded kindergarten called “The Little Butterflies” (Die kleinen Schmetterlinge) since September of the previous year, can now enjoy the large friendly rooms with a generously sized playroom especially for active play and encouraging movement. PTB’s old Guest House was rebuilt for the kindergarten group and it was also connected to the existing day care centre. The charity Johanniter-Unfallhilfe supports the kindergarten group as well as running the day care facilities which have already been set up on the PTB site. In contrast to the day care centre which takes children aged between one and three years if their parents work at PTB, “The Little Butterflies” is a kindergarten which is open to the general public. Anyone from Braunschweig is allowed to register their children at the kindergarten.

“It is important to us that our staff are able to have their children looked after on site, while having close contact with the nursery teachers,” explained PTB’s Equal Opportunity Commissioner, Birgit Behrens, who has constantly been the driving force behind setting up PTB’s own day nursery as well as the kindergarten. “We have had the support of PTB’s Presidential Board the whole time and are very pleased to have found just the right partner for this great project in the Johanniter-Unfallhilfe,” she said while taking stock during the opening ceremony.

With the kindergarten, a whole ensemble of buildings for children has now been created between the Central Building and the Paschen Building. Besides the indoor and outdoor facilities of the day care centre and the kindergarten, the new WissensForscher-Labor (KnowledgeSearchers Lab) for primary school children has also been built. In total, PTB has invested 1.1 million euros in these building measures.

Quality Management

Recognition of verification certificates

According to section 6, subsection 2 of the German Units and Time Act, PTB is responsible for realizing, maintaining and disseminating the units in Germany. Furthermore, PTB has the legal task of ensuring the uniformity of metrology in Germany – if applicable, together with third parties. This applies, e.g., to the cooperation with the German verification authorities. Ensuring the uniformity includes, in particular, the assessment of the metrological traceability by PTB. After the new Measures and Verification Act (Mess- und Eichgesetz (MessEG)) will have come into force as of 1 January 2015, this task will be confirmed and specified in section 47 of the MessEG.

In cooperation with PTB, the technical note 71 SD 0 005 on metrological traceability was published in August 2011 by DAkkS. In this way, DAkkS recognizes certificates of a verification authority as traceability proofs if this verification authority has successfully completed the assessment procedure by PTB for the respective measuring instrument category. The precondition for this assessment by PTB is a self-declaration of the corresponding verification authority, in which the verification authority confirms that the requirements of an effective quality system adapted to the current developments will be fulfilled. In many cases, these self-declarations are available on the Internet pages of the verification authorities.

In 10 of the, in total, 13 verification authorities, this assessment by PTB has so far been successfully carried out. All German federal states are involved in the assessment procedure. The results of the assessments and the measuring instrument categories in question have been published on PTB’s Internet page. Furthermore, the verification authorities are setting up – with the participation of PTB – a system of peer reviews to be able to prove the permanent compliance with the legal requirements.

The confirmation of the technical competence of the verification authorities by PTB concerning the metrological traceability will simplify the proof of competence required for the European Commission and the other Member States of the European Union and will avoid a double burden (through verification and, in addition, through calibration by accredited calibration laboratories) for the economic stakeholders.

Technology Transfer

Broader publication of PTB‘s technology transfer offers

According to its legal mission to promote the transfer of knowledge and technology, PTB has meanwhile set up its own sections on the subject of technology transfer in its print and internet media. Whether press releases about industrial fairs, contributions to PTB’s scientific newsletter “PTB News” or to the specialist journal “PTB-Mitteilungen”: in various formats, technology offers are presented which enable the companies to purchase licenses or to develop functional models together with PTB.

Within the European scope, the exploitation of research and development results for the European national economies – designated by the keyword “impact” – has gained considerably greater importance following the declaration of the “Innovation Union 2020” by the European Union. Here, PTB is prominently represented with currently 64 projects in the field of European Metrology Research Projects (EMRP) and the follow-up project European Metrology Programme for Innovation and Research (EMPIR) which is in its application phase. In tight periods under report, the latest results are published here in the work package “impact” by trade fairs and in PTB publications, and thus the economic stakeholders are addressed in a targeted way.

The technology offers are developed by the Technology Transfer Working Group in close coordination with the respective division and are then made available – in cooperation with the Press and Information Office – to a selected, but broad multiplier circle, e.g. in specialized journals or at internet technology platforms. Within the scope of the resulting new customer contacts, a project close to industry is frequently launched – together with the Division – by using the promotion possibilities for small and medium-sized enterprises, and at the end, a licence is allocated by PTB at conditions which are customary in the market.

PTB regards this as a contribution to the ambitious goal of developing “Europe into the most innovative national economy worldwide”, as has been proposed in the “Innovation Union 2020”.

Legal Metrology

Reorganization of legal metrology

With the new Measures and Verification Act, the reorganization of legal metrology was successfully completed in Germany in 2013. Together with the new Units and Time Act, the Measures and Verification Act assigns an important role to PTB in the field of metrology. Also in future, the aim will be to safeguard the existing confidence in official and commercial measurements as well as in measurements which are of public interest.

As of 1 January 2015, all those measuring instruments which are to be used within the scope of the Measures and Verification Act must have successfully undergone conformity assessment in order to be allowed to be placed on the market. In general, a conformity assessment body examines whether the essential requirements made on the measuring instrument have been met.

After they have been placed on the market, measuring instruments may be used until the verification period has expired. To be able to use the measuring instruments for a further verification period, the measuring instruments must be verified after the verification period has expired. Verification is carried out by the authorities which are in charge of this task under federal state law.

Rules and technical specifications for measuring instruments which are regulated at the national level as well as rules and findings on conformity assessment procedures are determined by the so-called Regelermittlungsausschuss (Rule Determination Committee). In addition, this committee also determines rules and findings for the use of measuring instruments or measurement values. The Regelermittlungsauschuss is composed of expert institutions and associations. These include PTB, the respective authorities of the federal states, conformity assessment bodies, state-accredited inspecting authorities, trade associations and consumer associations. PTB presides over the Regelermittlungsausschuss and houses its executive office.

In future, the committee for conformity assessment bodies, which will be presided over by PTB and in which conformity assessment bodies will participate, will make an important contribution to uniform working procedures of conformity assessment bodies.

For the use of new or renewed measuring instruments it will be required in future that these will be reported to the authority which is in charge of this task under federal state law six weeks after their putting into operation, at the latest.

According to the Measures and Verification Act, PTB’s legal tasks also include advising the federal state authorities which are in charge of implementing the act, to perform scientific research in this field, and to support standardization in this field. In addition, PTB also ensures the metrological traceability of the standard devices and of the test facilities of the conformity assessment bodies, of the respective authorities and of the state-accredited inspecting authorities.

Monitoring of the measuring instruments that have been placed on the market (market surveillance) is the task of those authorities which are in charge of it under federal state law. By means of suitable random samples, the market surveillance authorities carry out checks in order to find out whether measuring instruments comply with the legal requirements, and they take the necessary measures if they have reasonable suspicion that this is not the case. Within the scope of application monitoring, the authorities in charge verify whether the measuring instruments and the measurement values comply with the requirements which are specified in the Measures and Verification Act for their use.

Technical Cooperation

Quality for Africa

PTB’s Technical Cooperation with the African continent looks back on 45 years of experience. On the one hand, we have come to realize that promoting solely metrology in Africa does not make much sense; only a concerted interaction of all elements of the quality infrastructure as an instrument of development policy is a promising approach. On the other hand, it, however, also turned out that a continent home to 33 of the 45 least developed countries (LDCs) requires new conceptual approaches in order to ensure the efficient use of the extremely limited financial and human resources. Taking all this into consideration, PTB developed its own integrated pan-African strategy at a very early stage in order

International and pan-African Quality Infrastructure (PAQI)

to promote the quality infrastructure. “Quality for Africa” encompasses four fields of action: regional measures, national interventions, strategic alliances, and the promotion of institutions at the pan-African level.

The “Quality for Africa” concept is ambitious. It not only takes the requirements with regard to development policy prescribed by the Federal Ministry for Economic Cooperation and Development (BMZ) into account, but also those of the African Union. As early as in the founding treaty of the African Economic Community (AEC, Abuja Treaty, 1991), harmonized standards and procedures of quality assurance are mentioned. In the following years, innumerable other documents for the reduction of the barriers to trade within Africa were elaborated. The situation is precarious: the African share in world trade lies below 3 %, and trade within Africa only represents 0.5 % of total world trade.

In 1984, PTB began the organizational and institutional consultation of the African Organisation for Standards (ARSO). Twenty years later, the time had come for a pan-African metrology association to be established. After sorting out the last problematic issues and after clarifying what a metrologist deals with – namely neither with the weather forecast, nor with building underground train lines – the Intra-Africa Metrology System (AFRIMETS) was launched in Midrand, South Africa, in March 2006 with numerous international participants. Both before and after this milestone, PTB contributed significantly to shaping AFRIMETS. Strengthened by the positive experience, the creation of the African Accreditation Cooperation (AFRAC) was tackled with a run-in period of 3 years; its foundation ceremony and first general assembly took place in Cairo, Egypt, in September 2010. The last pillar of African QI institutions is the African Electrotechnical Standardisation Commission (AFSEC) – a subordinate organization of the African Energy Commission (AFREC) – which was founded in February 2008.

The presidents of the four pan-African organizations of quality infrastructure on the occasion of the signing of the Memorandum of Understanding on 30 August 2013 in Nairobi, Kenya.

What was still missing, though, was “recognition” by the African Union Commission (AUC). From 2011 on, PTB moderated several so-called “stakeholder meetings” in order to attain joint canvassing and proceeding. This gave birth to the exchange forum for the pan-African quality infrastructure (PAQI). In a declaration made at the Conference of African Ministers of Industry (June 2013), the ministers recognized PAQI “as the continental platform for all matters related to standardization, metrology, accreditation and conformity assessment”. In August 2013, the representatives of AFRAC, AFRIMETS, AFSEC and ARSO signed a Memorandum of Understanding (MoU) which designated PAQI as a joint forum allowing the possibility of contributing to Africa’s socioeconomic objectives in the field of quality infrastructure. PAQI’s most important organ is the Joint Committee which serves as the liaison office with AUC. AUC’s Director of Trade and Industry not only held the official opening speech, but also attended the first session of the Joint Committee.

Germany is the largest bilateral donor in the field of quality infrastructure in Africa. The major part of the technical consultation is processed by PTB. With the measures for organizational development, PTB has not only proven to be courageous and tenacious, but has also established itself as an “honest broker” of the African conception. The African continent has made its way onto the stage of international quality infrastructure. The cooperation network is self-supporting. The objective of “Quality for Africa” has not yet been achieved, but the cornerstone has been successfully laid.

Press and Information Office

Scientific journal maßstäbe focuses on the milestones of metrology

The most outstanding highlights from 125 years of metrological research are the subject of this year’s edition of maßstäbe (issue 12: Milestones). Thus, PTB’s scientific- journalistic journal focuses, for the first time, not on a single, but rather on a whole series of physical subjects – precisely those that shine the brightest in the history of the PTR and PTB.

The first of seven chapters in total (Das Körnige ( The granular)) deals with the investigation of black bodies which led Max Planck to the groundbreaking finding that energy only occurs portionwise. This marks the starting point of quantum physics. Even today, PTB uses black bodies for precision measurements.

A similar continuity is to be found in the investigation of superconductivity, which is the focus of the next chapter (Das Kalte (The cold)). A direct path leads here from the Meissner-Ochsenfeld effect to today’s use of superconductivity – for example, in the case of SQUIDs, in whose research PTB is today a world leader. And the series can be continued in this fashion: the invention of the Geiger counter, the Boltzmann Project and the Avogadro Project, optical atomic clocks, measurements accurate to the nanometer, or the exciting research surrounding the counting of single electrons – these are all examples of the PTR and PTB findings that have attained permanent importance. Thereby, the maßstäbe does not read like a history book, but rather starts in the present day: today’s application of the findings in physics and technology. Thus the picture is created of a research institute that is young at heart and highly versatile.