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News of the Year

Scientific Divisions

Single-electron current count checked

Single-electron current count checked

Single-electron pumps allow a current to be generated by trapping and transporting single electrons in a controlled manner. PTB has now succeeded in verifying the trapping statistics of a semiconductor single-electron pump for the first time by detecting single electrons with the aid of a special detector circuit.

In the future SI system, the physical units are to be defined by means of elementary fundamental constants such as Planck’s constant h or the charge of an electron e. The base unit of electric current, the ampere, can then be realized via a so-called “singleelectron pump”. The single-electron pump consists of a microscopic semiconducting island with two current leads. In pumping operation, first an electron coming from the current lead on the left is loaded onto the island and then released into the other current lead. If this procedure is repeated periodically at a clock frequency ƒ, a current I = eƒ is generated. The current is then only determined by the fundamental constant of the charge of an electron e, and the clock frequency ƒ. At present, semiconductor- based single-electron pumps are considered the most promising candidates for the future realization of the ampere.

In the past, to characterize such a single-electron pump, the pump had to be operated continuously with a given frequency f, and the current generated thereby had to be measured as precisely as possible. Such a measurement, however, always implies an averaging over numerous clock cycles, so that the data concerning single, rarely occurring pump errors are eventually lost. The actual number of these pump errors is, however, of vital importance for metrological applications. In the year under report, PTB was able, for the first time, to integrate and test a detector circuit together with a single-electron pump on one chip (see figure). The detector circuit allowed single errors of such pumps to be detected and analyzed.

The detector circuit is based on so-called “singleelectron detectors”. These detectors react so sensitively to electric charges that they can even definitely detect the only electron that is trapped and transported by the pump per clock cycle. With the aid of this detection method, the error rate of the pump has now been measured precisely as a function of various external parameters. Excellent agreement was yielded when comparing the measured error rate with theoretical predictions; this confirmed the validity of the model used. In addition, it turned out that under the given conditions of measurement, the thermal distribution of the electrons on the island did not have a significant influence on the error rate. These results are a decisive step towards the future development of a semiconductor-based single-electron current standard.

PTB’s new laser hygrometer in operation in the stratosphere

PTB’s metrologic capabilities reach up to the stratosphere! Within the scope of a cooperation with Forschungszentrum Jülich, a high-precision – and, above all, calibration-free – laser hygrometer was developed; due to its precise and fast water measurements in the atmosphere it allows, for example, novel investigations to detect clouds and to improve the understanding of clouds and their evolution dynamics. The hygrometer is used on board the new research aircraft “HALO” (High-Altitude and LOng-Range Research Aircraft) and was successfully tested on the occasion of a first measurement campaign over a distance of 100,000 km.

the water vapour content is considered a particularly important measurement quantity. On the one hand, water vapour itself is the most important greenhouse gas and also has an impact on the climate in its condensed form, namely via clouds; on the other hand, numerous gas-analytical procedures have to be corrected for the water vapour content. The multi-channel hygrometer “HAI” developed by PTB and Forschungszentrum Jülich (FZJ) allows for the first time the simultaneous multi-phase H2O measurement with one single measurement principle, i.e. an extractive determination of the total water content where all water molecules in the form of ice, water droplets and water vapour are led into a closed measuring cell via an air inlet vent at the same time as a sample-free, in-situ determination of the sole water vapour by means of an open multireflex cell located on the outer shell of the aircraft. In order to cover the large water vapour range between the troposphere (approx. 20,000 ppmv) and the stratosphere (4 ppmv), a double-wavelength hygrometer was developed for the first time; it works simultaneously with two lasers at 1.4 μm or 2.6 μm, respectively. In addition, HAI is also exceptionally fast and can acquire data with a measuring. frequency of more than 100 Hz.

Research project on the measuring cartridge issue of water and heat meters successfully completed

Water and heat meters are subject to legal verification and therefore have to meet the requirements of the European Measuring Instruments Directive (MID). Whether also the measuring cartridge version of these instruments complies with these requirements has now been checked within the scope of an extensive research project. Extensive investigations were carried out on various configurations. The results clearly showed that also single- and multi-jet cartridge meters comply with the requirements of the MID and can, thus, be used in applications subject to legal control without concern. The research project was carried out jointly by PTB and the Verband der Deutschen Wasser- und Wärmezählerindustrie (VDDW) as well as the Arbeitsgemeinschaft Heizund Wasserkostenverteilung (ARGE HKV).

Measuring cartridge meters of various designs and sizes were investigated as to their behaviour in the event of flow disturbances; for this purpose, not only the bluff bodies (swirl generators and diaphragms) standardized in international norms were used for the investigations, but also powerful means of flow constriction and covering of the incoming flow, which may occur in practice due to impurities or valves that are not fully open. For the first time, laser Doppler anemometry (LDA) was used inside the water meter in operation (with water flowing through it), as a non-contact method for the measurement and realization of velocity profiles.

Light-shift-free excitation of the octupole transition in 171Yb+

Light-shift-free excitation of the octupole transition in 171Yb+

Optical frequency standards are based on trapped atoms or ions with reference transitions in the optical spectral range whose natural linewidth is very small and whose frequency is, as far as possible, independent of the external fields acting on the atoms. At PTB, an optical frequency standard has been developed which exploits the “octupole transition” in a single ytterbium ion. The frequency shifts of this transition has been determined, and its frequency has been measured absolutely with a relative uncertainty of 8 ⋅ 10–16 which is limited by the caesium fountain reference. The result is in very good agreement with a measurement which was performed at the National Physical Laboratory (Teddington, UK) at virtually the same time.

According to quantum mechanics, the excitation of an octupole transition is highly forbidden and can only be achieved with a correspondingly high spectral excitation intensity. This causes the observed resonance frequency to shift from the unperturbed value. To date, absolute frequency measurements therefore had to be performed as extrapolation with different excitation intensities and independent, precise measurement of the relative intensity. Excitation according to the so-called “hyper”-Ramsey procedure provides a solution to this problem; within the scope of a cooperation between Russian, American and PTB scientists, it has recently been demonstrated that the interrogation of the clock transition with a special sequence of frequency- and phase jumps can render the undisturbed atomic transition frequency directly. This procedure has now been used for the first time at PTB to excite the Yb+ octupole transition; it allowed the suppression of the light shift to be demonstrated experimentally. By combining the maximum spectral resolution currently achievable with an optimized control of the experiment, it is possible to reduce the contribution of the light shift to the systematic uncertainty of the Yb+ octupole frequency standard to less than 10–17 .

Absolute length measurements at temperatures down to 7 K

In order to optimize the functioning of high-tech devices in various fields, increasingly precise knowledge of the thermal expansion of materials is required. For the European Space Agency (ESA), the behaviour of materials in the range of cryogenic temperatures is important for the performance of space telescopes. The large diameter of the primary mirrors of the telescopes and their operativeness at cryogenic conditions require ultra-stable components made of materials that must have been characterized very precisely with regard to the temperature dependence of their dimensions. The extreme requirements placed on the accuracy for the characterization of the thermal expansion (measurement uncertainty 3 · 10–9 K–1) can only be met by absolute length measurements by means of interferometry. This measurement procedure has been established at PTB for various measurement applications. It was, however, limited to a temperature range around 20 °C.

Within the scope of a project funded by ESA, PTB has, in cooperation with the TransMIT-Center of Adaptive Cryotechnology and Sensors, succeeded in clearly enlarging the temperature range of its newly set up ultra-precise interferometer also at cryogenic temperatures of down to 7 K. One of the greatest challenges within the scope of this project consisted in establishing methods to evaluate non-stationary interferograms from which the absolute length of test pieces of up to 50 mm can be determined over the whole temperature range from 300 K to 7 K with 1.5 nm accuracy. The first measurements have been performed with samples made of two different materials which come into question as substrates in space telescopes. In a subsequent step, the newly attained possibilities with the ultraprecision interferometer will be exploited to define extremely accurate standards to be used as a reference for indirect measurement procedures.

Redefinition of the Avogadro constant based on a decontaminated 28Si sphere

Within the scope of the suggested redefinition of the SI system of units, it is envisaged to base also the future definition of the SI unit of mass, the kilogram, on a fundamental constant. To this end, Planck’s constant, h, is considered; currently, its value is mainly defined by the experimental determination of the Avogadro constant, NA. In this context, PTB has, within the scope of the international Avogadro Project, contributed with essential measurands to reducing the relative measurement uncertainty of NA 10–8 A to 3 · –8 (metrologia 2011). Considerable progress has been achieved for the measurement of the crystal properties like lattice constant and molar mass. Unfortunately, the measurements carried out on the two Si spheres AVO28-S5 and AVO28- S8 polished by the Australian Centre for Precision Optics (ACPO) were influenced by a productionrelated slight contamination of the sphere surfaces with copper and nickel. These metals, in the form of silicide compounds, mainly affect mass determination, but also corrections on the results of the interferometric measurements for volume determination were necessary.

By means of multi-stage tests, it was possible to reduce the undesired contamination of the two 28Si spheres by metal silicides by at least two orders or magnitude. Hereby, a potential impairment of the roundness of the 28Si spheres was accepted. Subsequent measurements carried out in PTB’s sphere interferometer showed that, after decontamination, the roundness errors of one of the spheres (AVO28-S8) would still be suitable for a completely new measurement of the Avogadro constant. After determining the mass, the surface and the volume of the sphere, also a new Avogadro value was determined with the newly determined values. Whereas the mass reduction (amounting to 8.7 mg) and the diameter reduction (amounting to 273 nm) taken separately provided approximately consistent values, only the precise determination of the surface layers allows the correction specific to each of the measurands (mass, diameter).

The result showed that the decontamination allowed the uncertainty of the mass determination to be successfully reduced, but the etching process led to an increase in local disturbances of the diameter topography of the sphere. Due to this, the total uncertainty of the volume measurement increased. The numerical value of the Avogadro constant calculated on the basis of the decontaminated sphere (now designated as AVO28-S8b) NA = 6.022 140 66(28) · 1023 mol−1 is, however, in excellent agreement with the value published in metrologia for the AVO28-S8 sphere (NA = 6.022 140 76(19) · 1023 mol−1).

This, on the one hand, confirms the order of the corrections applied in the case of the contaminated sphere; on the other hand, it is also justifiable that a further improvement of the sphere’s topography can be expected to bring about a clear reduction of the total measurement uncertainty for the interferometric volume measurement. Taking the expected improvements into account for the future polishing of the sphere, which will take place at PTB, a relative total uncertainty for the Avogadro Project of < 2 · 10–8 is close at hand.

Underground laboratory UDO at a new location

In September 2012, PTB inaugurated its new underground laboratory (UDO II) at the 430 m level below ground in the Braunschweig-Lüneburg salt mine of the european salt company (esco) in Grasleben near Helmstedt. First measurements of the radiation level at UDO II yielded less than 2 nSv/h and a low radon activity concentration in the air. Thus, similarly good conditions to UDO in the Asse salt mine are found.

Over a period of almost 20 years, from 1991 to 2011, PTB operated the underground laboratory for dosimetry and spectrometry (UDO) in the Asse salt mine – initially at the 925 m level below ground and, later on, at the 490 m level below ground. At both sites, the laboratory was characterized by one of the lowest radiation levels worldwide, which – with 1 nSv/h – only amounted to approximately 1 % of the area dose rate on the surface. Besides the shielding of the cosmic radiation by the cover rock, this was especially due to the rock salt with an extremely low activity which surrounded the laboratory.

Following the classification of the Asse II mine as a nuclear installation in the context of the Atomic Energy Act, and the resulting change of the operator in January 2009, the utilization of the UDO laboratory in the Asse was possible only to a limited extent. In spring 2011, UDO had to be given up completely.

The tasks PTB had performed at UDO, however, will remain important to society for the correct calibration of dosimetry systems which are used throughout Europe for environmental monitoring at low exposure rates as they typically occur in the natural environment. With UDO II, comparably good measurement conditions have been restored at a new site for a longer term.

Large-area X-ray detector for low photon energies

In cooperation with PTB, the Swiss company Dectris has developed a vacuum-compatible version of the “Pilatus” hybrid pixel detector for X-rays. This device now allows, for example, experiments for the size determination of nanoparticles to be carried out with Small-Angle X-ray Scattering (SAXS) also at the absorption edges of the light elements calcium, sulphur, phosphor or silicon at photon energies below 5 keV with high dynamics and good spatial resolution. This is of particular importance for the investigation of biological samples, for example within the scope of projects of the European Metrology Research Programme (EMRP), in the case of which complicated biological nano-objects and nanoparticles are to be dimensionally characterized in complex biological matrices in the PTB laboratory at the electron storage ring BESSY II, using SAXS measurements with synchrotron radiation. For this purpose, PTB has successfully commissioned the world’s first device of a vacuum-compatible Pilatus detector as a PTB facility of the largest scale.

In cooperation with the Helmholtz-Zentrum Berlin and the Institute for Molecular Pharmacology of the Hungarian Academy of Sciences, the first SAXS images of a multilamellar liposome sample were recorded on the Four-Crystal Monochromator (FCM) beamline in the PTB laboratory at BESSY II at a photon energy of 3 keV. The new detector consists of 10 modules which furnish – with a pixel size of 172 μm – a total area of 17 cm × 18 cm. It is also to be used for wide-angle scattering (WAXS), smallangle scattering (GISAXS) in reflection under grazing incidence, and other X-ray techniques.

Bayesian methods for uncertainty evaluation in regression problems

Regression problems often occur in metrology, e.g. in numerous calibration tasks. Currently, so-called “least-squares” methods are mainly used to solve these problems. Alternatively, Bayesian methods can be employed. In contrast to “least-squares” methods Bayesian procedures allow prior information to be taken into account in a natural manner. In addition, they enable the calculation of probability distributions for the measurands concerned. Hence, procedures based on Bayesian methods are being developed at PTB for uncertainty evaluation in regression problems.

An example for a regression problem is given by magnetic field fluctuation thermometry for which PTB has developed a specific Bayesian analysis scheme. The figure shows the probability distributions determined by the new method which enables a more reliable evaluation of measurement uncertainties.

The development of methods for uncertainty evaluation for regression problems also is a central topic within the EMRP Project “Novel mathematical and statistical approaches to uncertainty evaluation”, which is coordinated by the PTB and which was launched on 1 August 2012. Eleven European partners, as well as six international collaborators from North America, South America, and Asia, among others are involved in this project.

Advisory Board

The 63rd meeting of the Kuratorium (Advisory Board) of PTB

The annual meeting of the Kuratorium (Advisory Board) of PTB took place this year in Braunschweig on 24 and 25 May. The members of the Kuratorium and guests were welcomed for the first time by the new President of PTB, Prof. Dr. Joachim Ullrich. Following this, as happens every year, the members of the Kuratorium had the opportunity to visit a selection of PTB’s measurement facilities and thus to gain an insight into some of the ongoing research and service tasks. Later in the afternoon of the first – traditionally technically oriented – day, a PTB open colloquium was held, in which young scientists presented their fields of work. This year there was a wide range of subjects with presentations by Makram Anwar Zebian on “Ear canal probes for measuring otoacoustic emissions”, by Dr. Erik Benkler on the subject of “Fast optical synthesizers” and by Franziska Renner about a “Benchmark experiment for the verification of radiation transport calculations for dosimetry”. There was subsequently time for the members of the Kuratorium to hold intensive discussions in PTB’s specialist divisions.

The meeting of the Kuratorium on 25 May 2012 was opened by the President of the Kuratorium, Dr. Sven Halldorn (BMWi), who particularly welcomed PTB’s new President. In his speech Dr. Halldorn promised that the BMWi would support PTB in its efforts for a follow-up programme to the very successful ongoing EMRP (European Metrology Research Programme), namely the EMPIR (European Metrology Programme for Innovation and Research). In future PTB will have to increasingly face large new social challenges which – like the energy transition (transformation of the energy system away from nuclear power) – place special demands on metrology. Dr. Halldorn emphasized that PTB – also in future – will continue to play an important role in legal metrology and in the field of standardization. To successfully implement its wide range of tasks, PTB needs good framework conditions, equivalent to those which are opened to non-university research institutions with the “Wissenschaftsfreiheitsgesetz” (Academic Freedom Act). The BMWi will advocate this.

Following this, Prof. Ullrich gave an overview of the most important work performed by PTB in the past year. In his speech he reported on the current status of the redefinition of the base units and explained in detail PTB’s planning for the continuation of the work that was started in the scope of the Avogadro Project. Within this project, the Avogadro constant is being determined with an accuracy which has so far not yet been attained, which is simultaneously opening a way for the re-definition and the primary realization of the kilogram. Prof. Ullrich furthermore reported that the EMRP has become one of the main pillars of the research activities of PTB. The continued increase in the number of non-permanent staff members due to the continuous cutbacks in permanent staff will – in the coming years – increasingly create problems, as sufficient staff numbers will no longer be available to carry out the service tasks which have to be fulfilled.

The following changes to the members of PTB’s Kuratorium will take place:
Dr. Wolfgang Schwitz has retired from the Kuratorium; the Extension Committee has suggested three new members to be appointed to the Kuratorium, who have been endorsed by the Kuratorium. The appointment of the new members of the Kuratorium, Dr. Kayser-Pyzalla, Dr. Burger and Dr. Petit, has since been made by the BMWi.

Presidential Board

Retirement ceremony for Prof. Dr. Ernst O. Göbel

Within a ceremony on 20 January 2012 in the presence of the Federal Minister of Economics Dr. Philipp Rösler, Prof. Dr. Ernst O. Göbel, who had been President of PTB for 16 years, was given his official farewell and his successor, Prof. Dr. Joachim Ullrich, took office. In the presence of numerous prominent guests from politics and the scientific community, such as the Nobel Prize winner Prof. Dr. Klaus von Klitzing, Prof. Göbel’s work in the last 16 years was honoured by numerous speakers, including the university presidents Prof. Dr.-Ing. Jürgen Hesselbach (TU Braunschweig) and Prof. Dr.- Ing. Erich Barke (Leibniz Universität Hannover). “Professor Göbel has in his 16 years as President of PTB nationally and internationally promoted its reputation as an excellent research institute in the field of metrology as well as a reliable and competent service provider in all issues related to metrology. For this, he deserves our highest recognition,” said Minister Rösler in his speech at the event.

Prof. Göbel’s successor as president is the physicist Prof. Dr. Joachim Ullrich, who left the Max Planck Institute for Nuclear Physics (MPIK), Heidelberg, for PTB. Federal Minister Rösler said: “With Professor Ullrich we have now been able to attract an excellent physicist as the successor to the office of president. He will be the 14th president in the 125- year history of PTB.” Prof. Ullrich, born in 1956, director and scientific member of the MPIK for ten years, headed the “Experimental Few-Particle Quantum Dynamics” Division there. Prof. Ullrich’s background in physics lies in atomic, molecular and laser physics as well as in precision spectroscopy. “I wish my successor all the best, along with much success in his new office and hope that he always has a good sense of the right metrological course,” said Prof. Göbel.

Awarding of the Helmholtz Prize 2012

In Braunschweig’s Civic Centre (Stadthalle Braunschweig) on 27 March 2012 following this year’s Helmholtz Symposium, the Helmholtz Prize 2012 was awarded to Sven Sturm, Anke Wagner and Prof. Dr. Klaus Blaum of the Max Planck Institute for Nuclear Physics in Heidelberg and of the Johannes Gutenberg University Mainz for the determination of the g-factor of highly charged ions. The measurements carried out by the award winners allow the verification of predictions of quantum electrodynamics, the fundamental theory of electromagnetic interaction, with a precision as yet unattained in bound systems.

The Helmholtz Prize of the Helmholtz-Fonds e.V. (Helmholtz Fund) and the Stifterverband für die Deutsche Wissenschaft, endowed with € 20 000, is awarded every 2 to 3 years for outstanding scientific and technological research in the field of precision measurement in physics, chemistry and medicine.

Before the prize was awarded, a one-day Helmholtz Symposium with 650 participants took place. In seven lectures international experts gave an overview of current metrological issues. These included fundamental considerations on the consequences of a redefinition of the SI base units, application-specific questions in the field of metrology for medicine as well as precision measurements for the verification of fundamental questions of modern physics, for instance, how they can be addressed with gravitational wave detectors. A wide range of subjects was thus covered and the theme “Metrology, the Universe and Everything” was reflected.

Visit of State Secretary Beerfeltz to PTB

On 1 November 2012 Hans-Jürgen Beerfeltz, State Secretary of the Bundesministerium für wirtschaftliche Zusammenarbeit und Entwicklung (Federal Ministry for Economic Cooperation and Development – BMZ), visited PTB. During a discussion with the Presidential Board and through visiting two of PTB’s departments, he got an impression of the aims and tasks of PTB, with special emphasis on the international activities. PTB has undertaken projects in partner countries for over 40 years with the financial support of BMZ. These projects aim at developing and extending a quality infrastructure. State Secretary Beerfeltz used the opportunity to get to know PTB’s staff members who are active in this field and was given a close insight into some of the projects. “With PTB, Germany has, as the only bilateral donor, an internationally recognized specialized institution which conducts technical and political consulting services in the area of quality infrastructure for us. It is impressive that PTB combines the triad of science, the economy and development with commitment and has taken on responsibility for this worldwide. Only when countries harmonize and mutually recognize standards and technical regulations, will globalization become a success story for everyone,” said State Secretary Beerfeltz.

Technology Transfer

Professional patent exploitation leads to considerable revenues from licenses

Patent exploitation of PTB enables the licencees to develop new fields of business and generates considerable licence revenues for PTB. In 2012, the outcome of the previous year was exceeded again, resulting in a total amount of 1.1 million euros for the last four years.

The number of actively supported licensing procedures amounts to 150. With 60 licensing agreements for patents or technologies, the exploitation rate is unusually high. These PTB technologies allow the licence holders to establish new fields of business, mostly in the area of ultra-precision metrology. The most successful licensed technologies are utilized in many promising sectors and in multi-facetted applications. These include medical engineering, dosimetry, coordinate metrology, building physics and process technology. They thus contribute to the creation and preservation of jobs, especially in the field of medium-sized enterprises.

For four years now, the surpluses have been clearly higher than the external costs. The figure shows the typical mismatch between the beginning of the patenting and the first proceeds of five years. The oneoff effects have been highlighted in colour, these include patent sales and, in the last year, above-average revenues in the area of high-precision neutron dosimeters due to the tragic accident in Fukushima. Thus, the revenues from licences finance the patent costs and the inventors’ bonuses. In future, an even closer dovetailing of industry-oriented research of the diverse PTB departments with patent exploitation is planned. The essential macroeconomic objective is to apply the results of the academic research more rapidly and in a more targeted way to industrial applications.

Quality Management

Successful re-evaluation of PTB’s quality management by EURAMET within the scope of the CIPM-MRA

Since the signing of the Mutual Recognition Arrangement of the International Committee for Weights and Measures – CIPM-MRA in October 1999, PTB and its designated institutions (the Federal Institute for Materials Research and Testing – BAM, the Federal Environment Agency – UBA and the Federal Ministry of Consumer Protection and Food Safety – BVL) have been acknowledged and valued participants of this arrangement. All participants must provide evidence of the permanent and effective operation of a quality management system (QMS). This is verified every year by an internationally agreed-upon review procedure. Every five years, a comprehensive evaluation of the QMS is required..

This re-evaluation of the German metrological laboratories was carried out by EURAMET TC Quality in March 2012. The German institutions under the direction of PTB thereby successfully proved that the requirements of the CIPM-MRA with regard to quality management are entirely fulfilled. The preconditions of this confirmation by EURAMET are a report on the QMS development within the period of 2007–2011 and the Annual Reports. The procedure was concluded by an oral presentation. In a comprehensive discussion, the focal points of the further development of the quality management were presented by PTB. BAM supplemented this presentation with information on the manufacturing of reference materials in chemistry.

The successful evaluation by EURAMET is the precondition for the unlimited worldwide recognition of certificates for more than 1,600 calibration and measuring capabilities of the German metrology system. In order to keep the customers and partners of PTB comprehensively informed, PTB’s complete quality manual and the self-declaration on quality management – besides these metrological and calibration capabilities – are also made available on the Internet.

Assessment of the metrological traceability in legal metrology

According to section 6, subsection 2 of the Units and Time Act, PTB has the task of ensuring the uniformity of metrology in Germany when PTB performs this legal task 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.

In seven of the, in total, 13 verification authorities, this assessment was successfully carried out in 2012. The focus was, thereby, on the competent application of the metrological traceability according to the latest state of the art. Altogether, 10 federal states are involved in the assessment; for 4 other federal states, the assessment is just being prepared. Furthermore, the verification authorities – with the participation of PTB – set up a system of peer reviews to be able to prove the permanent compliance with the legal requirements.

The confirmation of technical competence by PTB will simplify the proof of competence which will be required in future for the European Commission and the other Member States of the European Union. Furthermore, the assessment of the metrological traceability by PTB is the precondition for the verification certificates to be used also as proof of traceability in accredited institutions and for them to be accepted by the German Accreditation Body (Deutsche Akkreditierungsstelle – DAkkS). This can help to avoid the economic agents being charged double by a verification and an additional calibration of measuring instruments.

Technical Cooperation

A Quantum of QI

Das 125-jährige Jubiläum der PTB und das 50-jährige Bestehen des Bundesministeriums für wirtschaftliche Zusammenarbeit und Entwicklung (BMZ) waren zwei gute Anlässe, einen großen Workshop zum Thema Qualitätsinfrastruktur (QI) zu veranstalten. Der Einladung der PTB folgten mehr als 200 Metrologen aus 115 Ländern.

Zum Warm-up wurde die Veranstaltungshalle in eine Landkarte verwandelt und alle Teilnehmer wurden aufgefordert, sich zu ihrem Heimat-Kontinent zu begeben. Das bot nicht nur einen ersten Überblick auf die Verteilung der Teilnehmer, sondern bot auch neue Kontaktmöglichkeiten für jüngere Kooperationsmitglieder. Auch die Gruppierung nach Länge der bestehenden Kooperationen war sehr aufschlussreich. Weiter ging es im Sitzungssaal mit einem Einführungsvortrag von Abteilungsleiterin Uta Böllhoff vom BMZ und weiteren Vorträgen. In der anschließenden Podiumsdiskussion ging es um das Thema „Entwicklungskooperationen – wirtschaftliche Entwicklung“. Die sechs Teilnehmer berichteten von ihren Erfahrungen und den Rahmenbedingungen in ihren Ländern.

Während des Programms wurde auch ein Projektvertrag zum Aufbau einer „Qualitätsinfrastruktur für Erneuerbare Energien und Energieeffizienz in Lateinamerika und der Karibik“ öffentlich unterzeichnet. Oscar Harasic von der Organization of American States (OAS) betonte, dass erneuerbare Energien und Energieeffizienz wichtige Zukunftsthemen in Lateinamerika und in der Karibik seien. Qualität und Qualitätssicherung spielten bei der Technologieentwicklung sowie der Einführung, Verbreitung und Förderung der erneuerbaren Energien und der Energieeffizienz eine wichtige Rolle.

Die drei regionalen Qualitätsfachorganisationen für Metrologie Sistema Interamericano de Metrologia (SIM), Normung Comisión Panamericana de Normas Técnicas (COPANT) und für Akkreditierung InterAmerican Accreditation Cooperation (IAAC) sowie die OAS und die PTB werden in den nächsten Jahren im Rahmen des unterzeichneten Projekts eng zusammenarbeiten. Erklärtes Ziel ist die Stärkung der technischen Basis zur Qualitätssicherung und damit zur erfolgreichen Umsetzung nationaler Energiepolitiken zur Förderung erneuerbarer Energien und der effizienten Energienutzung. Das Vorhaben wird sich zunächst auf Dienstleistungen der Qualitätsinfrastruktur für die Bereiche Solarthermische Anlagen, Energieeffizienz von Haushaltsgeräten sowie Smart Grids konzentrieren. Langfristig sind auch Aktivitäten in den Bereichen Windenergie und energieeffiziente Gebäude vorgesehen.

Viele der Teilnehmer nutzten die Gelegenheit, der PTB in schriftlicher Form zu gratulieren und den Veranstaltern Gedanken, Wünsche oder Ideen mitzuteilen. Anhand der vielen Grüße und Kommentare wurde die hohe Anerkennung der PTB in allen Kontinenten der Erde eindrucksvoll dokumentiert.

„A Quantum of QI“ wurde von allen Teilnehmern genutzt, um neue Kontakte zu knüpfen und bestehende zu pflegen. Dies und die fachlichen Inhalte machten den Workshop zu einer erfolgreichen Veranstaltung, bei der die Welt zu Gast bei Freunden in Braunschweig war.

Legal Metrology

Standardization as an important regulation tool of legal metrology in Europe

The European Measuring Instruments Directive [1] regulates, within the scope of the New Approach [2], the harmonized placing of 10 measuring instrument categories on the EU Single Market. The essential requirements placed on these measuring instruments are laid down bindingly in the Directive itself and are intended to provide and guarantee a high level of protection.

The technical specifications are laid down in harmonized standards or in normative documents whose application remains voluntary, and the manufacturers are always free to use other technical specifications in order to comply with the requirements.

For measuring instruments that have been manufactured in accordance with the harmonized standards or with the normative documents, it is presumed that they fulfil the respective essential requirements of the Measuring Instruments Directive.

To make the New Approach work, the standards must warrant a certain quality which is in compliance with the essential requirements laid down in the Directives. The European organizations for standardization have the complete responsibility for the technical content of these standards.

In principle, the search for technical solutions is left to the interested parties, and there is no provision in the New Approach which would stipulate that the content of harmonized standards or normative documents which have been duly adopted in accordance with the standardization procedure has to be tested and approved by public authorities at the national or at the European Community level.

Both European standardization and the standardization strategy of the German Federal Government [3] are based on the standardization principles approved by the World Trade Organization. The elaboration of standards shall follow pre-defined principles so that the legislator can refer to them. Important principles are: the collaboration of all the parties concerned; the principle of the unanimous vote; transparency; accessibility; consistency of the set of standards; and the involvement of the public in the elaboration of the standards. The balanced participation of all the circles concerned (such as, e.g., the representatives of large, medium-sized and small industrial enterprises, the representatives of the service providers, of the authorities, of the social partners, of consumer protection, of environmental protection and of occupational safety) in the steering and working committees of standardization must be made possible not only formally but also in practice. This is the precondition for the legitimation, acceptance and application of standards and must therefore be supported.

By involving the authorities in the standardization process it should be possible to ensure that public interests will be adequately considered in the standardization process.

The European organizations for standardization must not necessarily submit newly elaborated standards as harmonized standards. They can also choose existing standards which – after they have these examined and, possibly, revised – they consider to be sufficient for the requirements of the standardization order, or which they can modify accordingly. Furthermore, it is possible for them to declare international or national standards as European standards and to submit them to the Commission as harmonized standards.

A harmonized standard must comply with the essential requirements of the respective Directive. A European standard can contain provisions which not only refer to the essential requirements but also to other provisions. In that case, these other provisions must be clearly distinguished from the provisions which are related to the essential requirements.

Furthermore, a harmonized standard might not necessarily cover all the essential requirements. The manufacturer would then be obliged to consult other relevant technical specifications in order to do justice to all the essential requirements laid down in the Directive.

[1] DIRECTIVE 2004/22/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL dated 31 March 2004 on measuring instruments
[2] Blue Guide – Guide to the implementation of directives based on the New Approach and the Global Approach (2000)
[3] Standardization strategy of the German Federal Government (2009)

Press and Information Office

125 years pecisely – PTB celebrated its birthday

If you want to know how to measure truly accurately, the Physikalisch-Technische Bundesanstalt (PTB) is precisely the place to be. And this is not just the case nowadays, but rather it has been so for precisely 125 years. When the first budget of the Physikalisch- Technische Reichsanstalt (PTR), the predecessor of PTB, was approved on 28 March 1887, this was the birth of the first state-run, non-university, major research institution and the beginning of a metrological success story that hasn’t ended yet by a long shot. On this occasion, PTB, the National Metrology Institute of Germany (NMI) celebrated its birthday on 28 March 2012. PTB was celebrating with a political ceremonial act at the Braunschweiger Stadthalle (Braunschweig Civic Centre) and – on the day before – with a scientific symposium which people from all over the world were attending.

Nowadays, accuracy is in demand at all levels to push developments in the right directions: whether in industrial processing or for the diagnostic methods of medicine, whether in chemical analysis or in fundamental scientific research. Metrology, the science of accurate measurement, is in demand at all these levels and in all these disciplines, and far beyond. The scientific symposium “Metrology, the Universe and Everything” (the title is based – in a tongue and cheek manner – on Douglas Adams’ book “The Hitchhiker’s Guide to the Galaxy”) highlighted this broad field of tasks on 27 March in the Braunschweiger Stadthalle (Braunschweig Civic Centre) in several survey lectures, without claiming to have the final answers to the very first questions. As regards content, the symposium spanned an arc, from the growing importance of the fundamental constants for the definition of the physical base units to the concrete metrological applications in our everyday world. At the conclusion of the symposium, the most important prize in metrology, the Helmholtz Prize, was awarded.

The actual anniversary ceremonial act on 28 March was less a matter of scientific accuracy, but perhaps more a matter of accurate scientificpolitical classifications. Following the welcome address by Prof. Dr. Joachim Ullrich (PTB President since the beginning of this year), several speeches were given by leading politicians from the federal government, the federal state and the city are on the agenda. The commemorative lecture was given by the winner of the Nobel Prize in Physics, Prof. Dr. Klaus von Klitzing, who has been closely connected to PTB since his discovery of the quantum Hall effect and who holds the office of vice-president of the PTB Kuratorium (Advisory Board). A short scientific historic lecture on 125 years of PTR/PTB was given by Prof. Dr. Ernst O. Göbel (President of PTB from 1995 to 2011).

Rededication of the renovated Observatory

On the occasion of its 125th anniversary, PTB also celebrated the rededication of its oldest building, the Observatory, which dates back to 1891. At that time, Werner von Siemens had financed its planning and the initial construction work even before the budget for the founding of the PTR was approved by the Imperial Diet. Hermann von Helmholtz exerted lasting influence on the design of the building, so that it can be considered as the first building worldwide that has been designed specifically for ideal laboratory conditions.

The history of the Observatory is associated with destruction, new beginnings, restoration and proper monument renovation, which is exemplary for the fate of the remaining historical buildings in existence in Berlin.

On 17 October 2012, thus exactly 125 years after the Technical Department of the PTR took up its work in rooms of the main building of today’s TU Berlin, the ceremonial rededication was held. Ruprecht von Siemens, the great-grandson of Werner von Siemens, drove the guests of honour in an original Siemens vintage car up to the entrance portal, where the traditional cutting of the – in this case blue – ribbon took place.

Now the Observatory shines in its new splendour and is again appreciated as a prominent gem. It accommodates laboratories of the medical- metrological departments: the 3T magnetic resonance tomography system in the former quartz clock basement (the first quartz clocks were developed here by Scheibe et al.) and the experimental infrastructure for biomedical optics form the basis for the leitmotif of Division 8: “From qualitative to quantitative medical imaging.”