161-545: The Physikalisch-Technische Bundesanstalt ( PTB ) is the national metrology institute of the Federal Republic of Germany , with scientific and technical service tasks. It is a higher federal authority and a public-law institution directly under federal government control, without legal capacity, under the auspices of the Federal Ministry for Economic Affairs and Climate Action . Together with NIST in
322-474: A board of directors , and the CGPM to a shareholders' meeting . The General Conference on Weights and Measures ( Conférence générale des poids et mesures or CGPM) is the principal decision-making body put on place by the convention. It is made up of delegates from member states and [non-voting] observers from associate states and economies. The conference usually meets every four years to receive and discuss
483-560: A "reunification in metrology". PTB took over parts of the ASMW (Office for Standardization, Metrology and Quality Control of the former German Democratic Republic), among them 400 employees, and the site Berlin-Friedrichshagen as additional field office (this has since been given up again). Other parts of the ASMW were integrated into the BAM . Despite a phase of staff reductions – after the strong expansion following reunification – PTB ranks today among
644-482: A 95% confidence that the measured value will fall inside the uncertainty interval. Other values of k can be used to indicate a greater or lower confidence on the interval, for example k = 1 and k = 3 generally indicate 66% and 99.7% confidence respectively. The uncertainty value is determined through a combination of statistical analysis of the calibration and uncertainty contribution from other errors in measurement process, which can be evaluated from sources such as
805-669: A CIPM report and endorse new developments in the SI as advised by the CIPM. The last meeting was held on 13–16 November 2018. On the last day of this conference there was vote on the redefinition of four base units, which the International Committee for Weights and Measures (CIPM) had proposed earlier that year. The new definitions came into force on 20 May 2019. The International Committee for Weights and Measures ( French : Comité international des poids et mesures , or CIPM)
966-519: A better basis for temperature measurement than did the triple point of water, as it overcame these difficulties. Over the next few years the support for natural constants grew and details were clarified, until in November 2018, the 26th General Conference on Weights and Measures voted unanimously in favour of revised definitions of the SI base units . The 2019 revision of the SI came into force on
1127-480: A conference in 1977 to develop international cooperation for accredited testing and calibration results to facilitate trade. In 2000, 36 members signed the ILAC mutual recognition agreement (MRA), allowing members work to be automatically accepted by other signatories, and in 2012 was expanded to include accreditation of inspection bodies. Through this standardisation, work done in laboratories accredited by signatories
1288-471: A consistent system of measures across the entire empire. However, after his death, the empire fragmented and many rulers introduced their own variants of the units of measure. Some of Charlemagne's units of measure, such as the pied du Roi (the king's foot ) remained virtually unchanged for about a thousand years, while others, such as the aune ( ell – used to measure cloth) and the livre ( pound ) varied dramatically from locality to locality. By
1449-580: A country's accreditation body must comply with international requirements and is generally the product of international and regional cooperation. A laboratory is evaluated according to international standards such as ISO/IEC 17025 general requirements for the competence of testing and calibration laboratories. To ensure objective and technically-credible accreditation, the bodies are independent of other national measurement system institutions. The National Association of Testing Authorities in Australia and
1610-503: A country's measurement infrastructure. The NMS sets measurement standards, ensuring the accuracy, consistency, comparability, and reliability of measurements made in the country. The measurements of member countries of the CIPM Mutual Recognition Arrangement (CIPM MRA), an agreement of national metrology institutes, are recognized by other member countries. As of March 2018, there are 102 signatories of
1771-670: A few years previously. Although France lost control of the metric system, they ensured that it passed to international rather than German control and that the international headquarters were in Paris. Spain notably supported France for this outcome and the first president of the International Committee for Weights and Measures, the Spanish geodesist, Carlos Ibáñez e Ibáñez de Ibero received the Grand Officer medal of
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#17327718611381932-483: A forum within the CIPM to ensure harmonization of measurement standards across many disciplines . In addition, what were originally conceived as standards for the purposes of trade have now been extended to cover a large number of aspects of human activity including medicine, science, engineering and technology. The metre convention was originally drawn up with the main purpose of providing standards of length and mass only. Standards relating to other quantities were under
2093-597: A group of researchers dealing with nuclear fission. Later, he took over the specialist area "nuclear fission" in the Reich Research Council which supervised, from spring 1942 on, the German uranium project. Shortly after that, Hermann Göring subordinated the working group under the former PTR physicist Kurt Diebner to Division V for atomic physics at the PTR. Esau received the title "Authorized Representative of
2254-646: A kilogram without an artefact the value of the Planck constant must be known to twenty parts per billion. Scientific metrology, through the development of the Kibble balance and the Avogadro project , has produced a value of Planck constant with low enough uncertainty to allow for a redefinition of the kilogram. Applied, technical or industrial metrology is concerned with the application of measurement to manufacturing and other processes and their use in society, ensuring
2415-1082: A lead NMI and several decentralised institutes specialising in specific national standards. Some examples of NMI's are the National Institute of Standards and Technology (NIST) in the United States, the National Research Council (NRC) in Canada, the Physikalisch-Technische Bundesanstalt (PTB) in Germany, and the National Physical Laboratory (United Kingdom) (NPL). Calibration laboratories are generally responsible for calibrations of industrial instrumentation. Calibration laboratories are accredited and provide calibration services to industry firms, which provides
2576-425: A metre deduced from the size of the earth". When the conference was reconvened in 1875, it was proposed that new prototype metre and kilogram standards be manufactured to reproduce the values of the existing artifacts as closely as possible. Although the new standard metre had the same value as the old metre, it had an "X" cross-section designed by Henri Tresca rather than a rectangular cross-section as this reduced
2737-503: A mutual acceptance arrangement (MAA) for measuring instruments that are subject to legal metrological control, which upon approval allows the evaluation and test reports of the instrument to be accepted in all participating countries. Issuing participants in the agreement issue MAA Type Evaluation Reports of MAA Certificates upon demonstration of compliance with ISO/IEC 17065 and a peer evaluation system to determine competency. This ensures that certification of measuring devices in one country
2898-465: A national measurement system to be recognized internationally by the CIPM Mutual Recognition Arrangement, an NMI must participate in international comparisons of its measurement capabilities. BIPM maintains a comparison database and a list of calibration and measurement capabilities (CMCs) of the countries participating in the CIPM MRA. Not all countries have a centralised metrology institute; some have
3059-588: A positive impact on GDP . In the United Kingdom, an estimated 28.4 per cent of GDP growth from 1921 to 2013 was the result of standardisation; in Canada between 1981 and 2004 an estimated nine per cent of GDP growth was standardisation-related, and in Germany the annual economic benefit of standardisation is an estimated 0.72% of GDP. Legal metrology has reduced accidental deaths and injuries with measuring devices, such as radar guns and breathalyzers , by improving their efficiency and reliability. Measuring
3220-1335: A purely metrological specialist journal and does not publish any "Official Notes" any more. Presidents of PTB and of the Physikalisch-Technische Reichsanstalt Berlin-Charlottenburg: Employees of PTR and PTB were, among others: Udo Adelsberger, Walther Bothe , Kurt Diebner , Gerhard Wilhelm Becker, Ernst Engelhard, Abraham Esau , Ernst Gehrcke , Hans Geiger , Werner Gitt , Eugen Goldstein , Ernst Carl Adolph Gumlich, Hermann von Helmholtz , Fritz Hennin, Friedrich Georg Houtermans , Max Jakob , Hellmut Keiter, Dieter Kind, Hans Otto Kneser, Friedrich Wilhelm Kohlrausch, Wilhelm Kösters, Bernhard Anton Ernst Kramer, Johannes Kramer, August Kundt , Max von Laue , Carl von Linde , Leopold Loewenherz, Otto Lummer , Walter Meidinger, Walther Meißner , Franz Mylius, Walther Hermann Nernst , Robert Ochsenfeld , Friedrich Paschen , Matthias Scheffler, Adolf Scheibe, Harald Schering , Reinhard Scherm, Johannes Stark , Ulrich Stille, Ida Tacke , Gotthold Richard Vieweg, Richard Wachsmuth, Emil Warburg , Wilhelm Wien . 52°17′43″N 10°27′49″E / 52.29528°N 10.46361°E / 52.29528; 10.46361 Metrology Metrology
3381-518: A report from the CIPM and to endorse new developments in the SI on the advice of the CIPM though at the 2011 meeting, it agreed to meet again in 2014 rather than 2015 to discuss the maturity of the new SI proposals . It is also responsible for new appointments to the CIPM and decides on major issues concerning the development and financing of the BIPM. According to the Metre Convention (Art. 4)
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#17327718611383542-814: A single kingdom, the Scots agreed to use the same units of measure that were already established in England. During the eighteenth century, in order to facilitate trade, Peter the Great , Czar of Russia adopted the English system of measure. From 1668 to 1776 the French standard of length was the Toise of Châtelet which was fixed outside the Grand Châtelet in Paris. In 1735 two geodetic standards were calibrated against
3703-529: A technical infrastructure and tools that can then be used to pursue further innovation. By providing a technical platform which new ideas can be built upon, easily demonstrated, and shared, measurement standards allow new ideas to be explored and expanded upon. Meter Convention The Metre Convention (French: Convention du Mètre ), also known as the Treaty of the Metre , is an international treaty that
3864-517: A time basis for this, PTB operates several atomic clocks (currently two cesium clocks and, since 1999 and 2009, respectively, two cesium fountain clocks). By order of PTB, the synchronization of clocks via radio is performed via the time signal transmitter DCF77 operated by Media Broadcast. Computers which are connected to the Internet can obtain the time also via the three public NTP time servers operated by PTB. In Berlin-Adlershof , PTB operates
4025-419: A time interval of 1/ 299 792 458 of a second". On 16 November 2018, the 26th General Conference on Weights and Measures (CGPM) voted unanimously in favour of revised definitions of some SI base units , in particular the kilogram. The new definitions came into force on 20 May 2019, but do not change the metre. The Convention created an international organization with two governing organs to facilitate
4186-402: A traceability link back to the national metrology institute. Since the calibration laboratories are accredited, they give companies a traceability link to national metrology standards. An organisation is accredited when an authoritative body determines, by assessing the organisation's personnel and management systems, that it is competent to provide its services. For international recognition,
4347-547: A very high precision. These projects provided tools that enabled alternative means of redefining the kilogram. A report published in 2007 by the Consultative Committee for Thermometry to the CIPM noted that their definition of temperature had proved to be unsatisfactory for temperatures below 20 K and for temperatures above 1300 K. The committee was of the view that the Boltzmann constant provided
4508-576: Is a collaboration of eight partner organisations: The JCGM has two working groups: JCGM-WG1 and JCGM-WG2. JCGM-WG1 is responsible for the GUM, and JCGM-WG2 for the VIM. Each member organization appoints one representative and up to two experts to attend each meeting, and may appoint up to three experts for each working group. A national measurement system (NMS) is a network of laboratories, calibration facilities and accreditation bodies which implement and maintain
4669-454: Is an organisation based in Sèvres, France which has custody of the international prototype of the kilogram , provides metrology services for the CGPM and CIPM, houses the secretariat for the organisations and hosts their meetings. Over the years, prototypes of the metre and of the kilogram have been returned to BIPM headquarters for recalibration. The BIPM director is an ex officio member of
4830-635: Is automatically recognised internationally through the MRA. Other work done by ILAC includes promotion of laboratory and inspection body accreditation, and supporting the development of accreditation systems in developing economies. The Joint Committee for Guides in Metrology (JCGM) is a committee which created and maintains two metrology guides: Guide to the expression of uncertainty in measurement (GUM) and International vocabulary of metrology – basic and general concepts and associated terms (VIM). The JCGM
4991-604: Is compatible with another country's certification process, allowing the trade of the measuring devices and the products that rely on them. WELMEC was established in 1990 to promote cooperation in the field of legal metrology in the European Union and among European Free Trade Association (EFTA) member states. In the United States legal metrology is under the authority of the Office of Weights and Measures of National Institute of Standards and Technology (NIST), enforced by
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5152-542: Is compatible with the certification process in other participating countries, allowing the trade of the measuring devices and the products that rely on them. The International Laboratory Accreditation Cooperation (ILAC) is an international organisation for accreditation agencies involved in the certification of conformity-assessment bodies. It standardises accreditation practices and procedures, recognising competent calibration facilities and assisting countries developing their own accreditation bodies. ILAC originally began as
5313-420: Is defined as the "property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty". It permits the comparison of measurements, whether the result is compared to the previous result in the same laboratory, a measurement result a year ago, or to the result of a measurement performed anywhere else in
5474-533: Is defined by the International Bureau of Weights and Measures (BIPM) as "the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of science and technology". It establishes a common understanding of units, crucial to human activity. Metrology is a wide reaching field, but can be summarized through three basic activities: the definition of internationally accepted units of measurement,
5635-414: Is hampered by one country not recognising the quality controls in place in other countries – often due to standards being different or being incompatible with each other. At the 20th CGPM (1995), it was recognized that although ad-hoc recognition of instrument calibration between cooperating countries had been taking place for a hundred years, a need had arisen for a more comprehensive agreement. Consequently,
5796-513: Is made up of eighteen (originally fourteen) individuals from a member state of high scientific standing, nominated by the CGPM to advise the CGPM on administrative and technical matters. It is responsible for ten consultative committees (CCs), each of which investigates a different aspect of metrology; one CC discusses the measurement of temperature, another the measurement of mass, and so forth. The CIPM meets annually in Sèvres to discuss reports from
5957-419: Is responsible for the running of ten consultative committees (CCs), each of which investigates different aspects of metrology – one CC discusses the measurement of temperature, another the measurement of mass and so on. The CIPM meets annually at Saint-Cloud to discuss annual reports from the various CCs, to submit an annual report to the governments of member states in respect of the administration and finances of
6118-563: Is the international standards, which beholds the world's standards. The next level is the national Metrology institutes that have primary standards that are traceable to the international standards. The national Metrology institutes standards are used to establish a traceable link to local laboratory standards, these laboratory standards are then used to establish a traceable link to industry and testing laboratories. Through these subsequent calibrations between national metrology institutes, calibration laboratories, and industry and testing laboratories
6279-627: Is the metrological specialist journal and the official information bulletin of PTB. It is published four times a year and contains original scientific articles as well as overview articles on metrological subjects from PTB's fields of activity. Each volume focuses on a main topic. As an official information bulletin, the journal stands in a long tradition which goes back to the beginnings of the Physikalisch-Technische Reichsanstalt (Imperial Technical Physical Institute - PTR, founded in 1887). Until 2014, "PTB-Mitteilungen"
6440-593: Is the scientific study of measurement . It establishes a common understanding of units, crucial in linking human activities. Modern metrology has its roots in the French Revolution 's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted
6601-640: Is to catalogue the capabilities of National Measurement Institutes (NMIs) such as NIST in the United States or the National Physical Laboratory in Britain whose calibration procedures have been peer-assessed. The essential points of CIPM-MRA are: Subsequent to launch of the CIPM MRA and in response to a European Community directive on in vitro medical devices, the Joint Committee for Traceability in Laboratory Medicine (JCTLM)
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6762-427: Is to fall within the uncertainty interval. Uncertainty is generally expressed as follows: Where y is the measurement value and U is the uncertainty value and k is the coverage factor indicates the confidence interval. The upper and lower limit of the uncertainty interval can be determined by adding and subtracting the uncertainty value from the measurement value. The coverage factor of k = 2 generally indicates
6923-532: The General Conference on Weights and Measures (CGPM) and the supervision of the International Committee for Weights and Measures (CIPM). These organizations coordinate international metrology and the development of internationally recognized systems of measurement . The Metre Convention established a permanent organizational structure for member governments to act in common accord on all matters relating to units of measurement. The governing organs of
7084-494: The Planck constant ( h ), the elementary electric charge ( e ), the Boltzmann constant ( k ), and the Avogadro constant ( N A ), respectively. The second , metre , and candela have previously been defined by physical constants (the caesium standard (Δ ν Cs ), the speed of light ( c ), and the luminous efficacy of 540 × 10 Hz visible light radiation ( K cd )), subject to correction to their present definitions. The new definitions aim to improve
7245-573: The Spanish Royal Academy of Sciences to approve the creation of a large-scale map of Spain. The following year Carlos Ibáñez e Ibáñez de Ibero was appointed to undertake this task. All the scientific and technical material had to be created. Carlos Ibáñez e Ibáñez de Ibero and Frutos Saavedra Meneses went to Paris to supervise the production by Brunner of a four metres long measuring instrument which they had devised and which they later compared with Borda 's double-toise No. 1, which
7406-672: The United Kingdom Accreditation Service are examples of accreditation bodies. Metrology has wide-ranging impacts on a number of sectors, including economics, energy, the environment, health, manufacturing, industry, and consumer confidence. The effects of metrology on trade and the economy are two of its most-apparent societal impacts. To facilitate fair and accurate trade between countries, there must be an agreed-upon system of measurement. Accurate measurement and regulation of water, fuel, food, and electricity are critical for consumer protection and promote
7567-473: The atomic clock it has been possible to define and measure International Atomic Time with sufficient precision that variations in the Earth's rotation can be detected. The International Earth Rotation Service monitors these changes relative to the stars at regular intervals and proposes leap seconds as and when these are needed. Currently there are over 200 atomic clocks in over 50 national laboratories around
7728-459: The quantum Hall effect for the ohm ), and the use of a material object as the measurement standard. A standard (or etalon) is an object, system, or experiment with a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures by realising, preserving, or reproducing a unit against which measuring devices can be compared. There are three levels of standards in
7889-505: The steelyard balance and other tools. Other civilizations produced generally accepted measurement standards, with Roman and Greek architecture based on distinct systems of measurement. The collapse of the empires and the Dark Ages that followed lost much measurement knowledge and standardisation. Although local systems of measurement were common, comparability was difficult since many local systems were incompatible. England established
8050-484: The 144th anniversary of the convention, 20 May 2019. The BIPM has two classes of adherents – full membership for those states that wish to participate in the activities of the BIPM and associate membership for those countries or economies that only wish to participate in the MRA programme. Associate members have observer status at the CGPM. Since all formal liaison between the convention organizations and national governments
8211-495: The Assembly invited British and American participation in the establishment of a new system, but in the event, the Assembly went it alone and introduced the metre and the kilogram which were to form the basis of the metric system, manufacturing prototypes which, in 1799, were lodged with Archives. The Helvetic Republic adopted the metric system in 1803. In 1805, a Swiss immigrant Ferdinand Rudolph Hassler brought copies of
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#17327718611388372-452: The Assize of Measures to create standards for length measurements in 1196, and the 1215 Magna Carta included a section for the measurement of wine and beer. Modern metrology has its roots in the French Revolution . With a political motivation to harmonise units throughout France, a length standard based on a natural source was proposed. In March 1791, the metre was defined. This led to
8533-511: The BIPM and to advise the CGPM on technical matters as and when necessary. Each member of the CIPM is from a different member state – with France, in recognition of its work in setting up the convention, always having one seat on the CIPM. The Secretariat (or Headquarters) of the International Bureau of Weights and Measures ( Bureau international des poids et mesures or BIPM) is based at Saint-Cloud, France. It has custody of
8694-408: The BIPM are: The headquarters or secretariat of the BIPM is at Saint-Cloud , France. It employs around 70 people and hosts BIPM's formal meetings. Initially the scope of the Metre Convention covered only units of mass and length. In 1921, at the sixth meeting of the CGPM, convention was amended to its scope to other fields in physics. In 1960, at the eleventh meeting of the CGPM, its system of units
8855-416: The BIPM to complete the task of defining all SI base units in terms of physical constants . By defining SI base units with respect to physical constants, and not artefacts or specific substances, they are realisable with a higher level of precision and reproducibility. As of the revision of the SI on 20 May 2019 the kilogram , ampere , kelvin , and mole are defined by setting exact numerical values for
9016-506: The CCs, to submit an annual report to the governments of member states concerning the administration and finances of the BIPM and to advise the CGPM on technical matters as needed. Each member of the CIPM is from a different member state, with France (in recognition of its role in establishing the convention) always having one seat. The International Bureau of Weights and Measures ( French : Bureau international des poids et mesures , or BIPM)
9177-538: The CGPM had 62 members and 40 associates. Membership in the CGPM requires payment of substantial fees. Being in arrears with these payments over a span of years has led to expulsion of some former members. Before the French Revolution , which started in 1789, French units of measurement were based on the Carolingian system, introduced by the first Holy Roman Emperor Charlemagne (800–814 AD) which in turn were based on ancient Roman measures. Charlemagne brought
9338-402: The CIPM MRA, consisting of 58 member states, 40 associate states, and 4 international organizations. A national metrology institute's (NMI) role in a country's measurement system is to conduct scientific metrology, realise base units, and maintain primary national standards. An NMI provides traceability to international standards for a country, anchoring its national calibration hierarchy. For
9499-485: The CIPM and a member of all consultative committees. The International Organization of Legal Metrology ( French : Organisation Internationale de Métrologie Légale , or OIML), is an intergovernmental organization created in 1955 to promote the global harmonisation of the legal metrology procedures facilitating international trade. This harmonisation of technical requirements, test procedures and test-report formats ensure confidence in measurements for trade and reduces
9660-491: The CIPM was mandated to investigate the setting up of a Mutual Recognition Agreement in respect of instrument calibration. Any such agreement would require the keeping of records that could demonstrate the traceability of calibrations back to the base standards. Such records would be recorded within an ISO 9000 framework. Four years later, in 1999 the text of the CIPM-MRA was agreed at the 21st CGPM. The CIPM-MRA scheme
9821-466: The Experimental and Research Reactor Braunschweig. This reactor served in particular as neutron source for fundamental research , not for the investigation of nuclear energy. PTB dealt with this controversial subject from 1977 to 1989, above all due to the fact that the task "long-term management and disposal of radioactive waste" had been assigned to it. Later on, this field of work passed over to
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#17327718611389982-635: The Federal Constitutional Court has declared the use of such voting machines to be inadmissible. Weapons which may be carried with the Minor Firearms Certificate, i.e. weapons for shooting blanks or irritants and weapons used as signaling devices, require a PTB test mark for their approval. Occasionally, these weapons are also jointly referred to as "PTB weapons" and bear the PTA or PTB proof mark F (see also: Act on
10143-485: The Franco-German War (1870/71), the stagnation in scientific mechanics and in the science of instruments had become evident in Germany. Increasingly precise metrology was required for industrial production. A considerable impact on the initiative for the founding of a state institute for metrology in order to promote the national interests of the economy, of trade and of the military was made – in particular – by
10304-633: The French metre and kilogram in the United States. In 1830 the Congress decided to create uniform standards for length and weight in the United States. Hassler was mandated to work out the new standards and proposed to adopt the metric system. The United States Congress opted for the British Parliamentary Standard Yard of 1758 and the British Troy Pound of 1824 as length and weight standards. Nevertheless,
10465-610: The Imperial Diet approved the first annual budget of the PTR – the founding of the first state-financed, university-external, major research institution in Germany which combined free fundamental research with services for industry. Werner von Siemens ceded private land in Berlin-Charlottenburg to the Reichsanstalt. Hermann von Helmholtz became its first president. At that time, 65 persons were employed at
10626-596: The International Committee for Weights and Measures (CIPM), was an advisory committee of metrologists of high standing. The third, the International Bureau of Weights and Measures (BIPM), provided secretarial and laboratory facilities for the CGPM and CIPM. The General Conference on Weights and Measures ( French : Conférence générale des poids et mesures , or CGPM) is the convention's principal decision-making body, consisting of delegates from member states and non-voting observers from associate states. The conference usually meets every four to six years to receive and discuss
10787-613: The International Union of Pure and Applied Physics and by the French Government to establish a practical system of units of measure, the CGPM requested the CIPM to prepare recommendations for a single practical system of units of measurement, suitable for adoption by all countries adhering to the Metre Convention. At the same time the CGPM formally adopted a recommendation for the writing and printing of unit symbols and of numbers. The recommendation also catalogued
10948-601: The Kuratorium and took over its competences himself. Jewish employees and critics of the NSDAP (such as Max von Laue ) were dismissed. After World War II , Von Laue participated in the re-founding of PTB. Albert Einstein , who had been thrown out of the Kuratorium already before its dissolution, broke ties to PTR/PTB. Under Stark and – after 1939 – under his successor Abraham Esau , the PTR strongly dedicated itself to armament research. A newly founded laboratory for acoustics
11109-738: The Légion d'Honneur for his diplomatic role on this issue and was awarded the Poncelet Prize for his scientific contribution to metrology. Indeed, as Carlos Ibáñez e Ibáñez de Ibero was collaborating with the French on the Paris meridian arc (West Europe-Africa Meridian-arc ) remeasurement since 1853, and was president of both the Permanent Committee of the International Metre Commission since 1872 and
11270-510: The MLS (Metrology Light Source) electron storage ring for calibrations in the field from the infrared (THz) to the extreme ultraviolet (EUV). Department Q.5 "Technical Cooperation" realizes projects of the German and international development cooperation in the field of quality infrastructure. These activities promote competitiveness as well as environmental protection and consumer protection in developing countries and in countries in transition. One of
11431-584: The PTB was dedicated at that time to the so-called New Physics . This included, among other things, research on the newly discovered X-rays, new atomic models, Einstein's Special Theory of Relativity, quantum physics (based on the already mentioned work on the black-body radiator), and the investigation of the properties of the electron. Scientists like Hans Geiger, who established the first radioactivity laboratory of PTR, were involved in this research work. Walther Meißner succeeded in liquefying helium , which led him to
11592-489: The PTR President Emil Warburg discontinued the subdivision into a physical and a technical division and re-structured the PTR into divisions for optics, electricity and heat, with sub-divisions of a purely scientific and technical nature. Under Warburg's successor Walther Nernst , the Reichsanstalt für Maß und Gewicht (Imperial Institute for Weights and Measures – RMG) was, in addition, integrated into
11753-517: The PTR successor. In 1948, Wilhelm Kösters, who had been the director of Division 1 in Berlin for many years, became its first president. Many former PTR employees from Berlin , Weida and Heidelberg followed him to Braunschweig. The new institute was named ꞋꞋPhysikalisch-Technische AnstaltꞋꞋ (PTA) and, since 1 April 1950, ꞋꞋPhysikalisch-Technische BundesanstaltꞋꞋ. In 1953, the West Berlin PTR
11914-400: The PTR was also closely connected with Max Planck. To decide whether electricity or gas would be more economic for street lighting in Berlin, the PTR was to develop a more precise standard for luminous intensity. For this purpose, in 1895, Otto Lummer and Wilhelm Wien developed the first cavity radiator for the practical generation of thermal radiation. Their measurements of the spectrum of
12075-497: The PTR was also closely connected with the armament industry of the Third Reich. Since exact measures are a basic requirement for the manufacture of military equipment, the PTR gained a key role in armament production and defense. The extent to which the PTR was also involved in the German nuclear weapons project is controversial. It is, however, known that – prior to his time as PTR president – Abraham Esau conducted – until 1939 –
12236-407: The PTR – among them more than a dozen physicists – who disposed of a budget of 263,000 Reichsmarks. In its first decades, the PTR succeeded in attracting important scientists and members of the Kuratorium as employees, among them Wilhelm Wien , Friedrich Kohlrausch , Walther Nernst , Emil Warburg , Walther Bothe , Albert Einstein and Max Planck . The first outstanding scientific achievement at
12397-514: The PTR. A newly established division took over from the RMG extensive tasks with regard to the verification system as well as the measurements of length, weight and volume associated with the verification system. The profile of tasks was thus similar to that of PTB today: Through its own research and development, and through services building on this, the PTR was to ensure the uniformity of metrology and its continuous further development. As regards contents,
12558-558: The Permanent Commission of the International Association of Geodesy since 1874, he was to play a pivotal role in reconciling French and German interests. The conference was called to discuss the maintenance of international standards based on the existing French standards rather than using French standards which, at that time, were 70 years old and which, through wear and tear, might not be exactly
12719-617: The President of the French Academy of Sciences is also the President of the General Conference on Weights and Measures. The International Committee for Weights and Measures ( Comité international des poids et mesures or CIPM) is made up of eighteen (originally fourteen) individuals from a member state of high scientific standing, nominated by the CGPM to advise the CGPM on administrative and technical matters. It
12880-729: The Proof Testing of Arms and Ammunition). The main site of PTB is in Braunschweig (Lehndorf-Watenbüttel). Other sites are in Berlin-Charlottenburg and Berlin-Adlershof . Divisions 1 to 6 as well as Division Q are located in Braunschweig. In Berlin-Charlottenburg Divisions 7 and 8 are located, and in Berlin-Adlershof the two electron storage rings BESSY II and the Metrology Light Source (MLS);
13041-599: The Reichsmarschall for Nuclear Physics", a post which he, however, ceded to Walther Gerlach already at the end of 1943. To escape the bombing raids of the allies , the PTR was, in 1943, relocated at the initiative of the president and Thuringian privy councillor Abraham Esau to different places in Germany (for example to Weida and Ronneburg in Thuringia and to Bad Warmbrunn in Lower Silesia). During
13202-415: The SI without changing the size of any units, thus ensuring continuity with existing measurements. The realisation of a unit of measure is its conversion into reality. Three possible methods of realisation are defined by the international vocabulary of metrology (VIM): a physical realisation of the unit from its definition, a highly-reproducible measurement as a reproduction of the definition (such as
13363-704: The Toise of Châtelet. One of them, the Toise of Peru was used for the French Geodesic Mission to the Equator . In 1766 the Toise of Peru became the official standard of length in France and was renamed Toise of the Academy (French: Toise de l'Académie ). Profusion of units of measures was a practical problem of importance before the French Revolution and its reform was one of the items on
13524-652: The USA and the NPL in Great Britain, PTB ranks among the leading metrology institutes in the world. As the National Metrology Institute of Germany, PTB is Germany's highest and only authority in terms of correct and reliable measurements. The Units and Time Act Bundesgesetzblatt (Federal Law Gazette), volume 2008, part I, No. 28, p. 1185 ff., 11 July 2008] assigns all tasks which are related with
13685-515: The agenda of National Assembly . In 1799, after the remeasurement of the Paris meridian arc (French: Méridienne de France ) between Dunkirk and Barcelona by Delambre and Mechain , the metre was defined as a quarter of a 10-millionth of the Earth circumference or 3 pieds (French feet) and 11.296 lignes (lines) of the Toise of the Academy. Talleyrand , an influential leader of
13846-589: The ampere be the base unit from which electromechanical standards would be derived. After negotiations with the CIS and IUPAP, two further base units, the degree kelvin and the candela were also proposed as base units. The full system and name "Système international d'unités" were adopted at the 11th CGPM. During the years that followed the definitions of the base units and particularly the mise en pratique to realize these definitions have been refined. The formal definition of International System of Units (SI) along with
14007-522: The associated resolutions passed by the CGPM and the CIPM are published by the BIPM on the Internet and in brochure form at regular intervals. The eighth edition of the brochure Le Système international d'unités – The International System of Units was published in 2006. During the 1940s, the United States government recognized the benefits of its suppliers keeping quality control records in respect of manufactured goods that would provide traceability of
14168-687: The attacks on Berlin, the buildings of the PTR were heavily damaged. In 1945, the Reichsanstalt was virtually destroyed and the few departments which still existed were scattered all over the country. Approximately from 1947 on, successor institutes were developed in addition to the PTR in Berlin-Charlottenburg, i.e. one in East Berlin – for the Soviet Occupation Zone – and one in the Bizone – and later Trizone . With
14329-407: The base units is to make the entire system derivable from physical constants , which required the removal of the prototype kilogram as it is the last artefact the unit definitions depend on. Scientific metrology plays an important role in this redefinition of the units as precise measurements of the physical constants is required to have accurate definitions of the base units. To redefine the value of
14490-410: The black-body radiation were so precise that they contradicted Wien's radiation law at long wavelengths. This caused one of the cornerstones of classical physics of that time to totter. The measurements prompted a decisive impulse on the part of Max Planck to divide thermal radiation – in an "act of despair", as he later declared – into separate portions. This was the birth of quantum physics. In 1914,
14651-454: The broad public. In addition, PTB publishes the scientific information bulletin PTB-news three times a year. On four pages, it contains news from the fields of work "Fundamentals of Metrology", "Applied Metrology for Industry", "Medicine and Environmental Protection", "Metrology for Society" and "International Affairs". The PTB-news are published in German and in English. PTB-Mitteilungen
14812-645: The case of France, via the French Foreign Minister and in the case of all other members, via the members' ambassador to France. The French government offered the treaty members the Pavillon de Breteuil in Saint-Cloud to house the BIPM. The Pavillon was originally built in 1675 on the estate of the Château de Saint-Cloud which was home to, amongst others, Emperor Napoleon III . The château
14973-511: The control of other bodies – time was measured by astronomers , electrical units by a series of ad-hoc international conferences, and other physical standards and concepts were maintained or defined by international bodies such as International Congress of Applied Chemistry or the International Union of Pure and Applied Physics . In 1901 Giorgi published a proposal for building a coherent set of units based on four base units –
15134-472: The costs of discrepancies and measurement duplication. The OIML publishes a number of international reports in four categories: Although the OIML has no legal authority to impose its recommendations and guidelines on its member countries, it provides a standardised legal framework for those countries to assist the development of appropriate, harmonised legislation for certification and calibration. OIML provides
15295-484: The creation of the decimal-based metric system in 1795, establishing standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure international conformity, the International Bureau of Weights and Measures ( French : Bureau International des Poids et Mesures , or BIPM) was formed by the Metre Convention . Although the BIPM's original mission
15456-569: The delegates (including the German delegation) were present. The International Metre Commission was established in Paris. Following the war, which resulted in Napoleon III's exile, Germany and Italy, now unified nations, adopted the metric system as their national system of units, but with the prototype copy of the kilogram and metre under the control of the French Third Republic . In 1872 the new republican government reissued
15617-555: The determination of fundamental and natural constants; the realization, maintenance and dissemination of the legal units of the SI; and safety technology. This spectrum of tasks is supplemented by services such as the German Calibration Service ( Deutscher Kalibrierdienst , DKD) and by metrology for the area regulated by law, metrology for industry, and metrology for technology transfer. As the basis for its tasks, PTB conducts fundamental research and development in
15778-460: The development of new measurement methods, the realisation of measurement standards, and the transfer of traceability from these standards to users in a society. This type of metrology is considered the top level of metrology which strives for the highest degree of accuracy. BIPM maintains a database of the metrological calibration and measurement capabilities of institutes around the world. These institutes, whose activities are peer-reviewed, provide
15939-479: The discovery of the superconductivity of a series of metals. In this connection, he recognized some years later – together with his colleague Robert Ochsenfeld – that superconductors have the property of displacing from their interior a magnetic field which has been applied from the outside – the Meißner-Ochsenfeld Effect. With the appointment of Johannes Stark as president on 1 May 1933,
16100-406: The earth. The conference recommended the adoption of the metric system (replacing Bessel 's toise, a copy of the Toise of Peru made in 1823) and the creation of an International Metre Commission. In the 1860s, inspections of the prototype metre revealed wear and tear at the measuring faces of the bar and also that the bar was wont to flex slightly when in use. In view of the doubts being cast on
16261-475: The easiest-observed societal impacts. To facilitate fair trade, there must be an agreed-upon system of measurement. The ability to measure alone is insufficient; standardisation is crucial for measurements to be meaningful. The first record of a permanent standard was in 2900 BC, when the royal Egyptian cubit was carved from black granite . The cubit was decreed to be the length of the Pharaoh's forearm plus
16422-561: The economy and politics. PTB is composed of the following nine divisions: Two essential factors which led to the founding of the Physikalisch-Technische Reichsanstalt (Imperial Physical Technical Institute – PTR) were the determination of internationally valid, uniform measures in the Meter Convention of 1875 and the dynamic industrial development in Germany in the 19th century. Already in
16583-438: The establishment of a state institute in order to solve this problem. The reason for this was that such a task was scientifically too ambitious for industrial laboratories and, in addition, not profitable for them, and classical training institutes were not suited for the task either. Among the supporters of the "Schellbach Memorandum" (named after its author Karl Heinrich Schellbach) ranked, among others, Hermann von Helmholtz and
16744-456: The existing metre and kilogram artefacts that were held by the French Government and the setting up of an organization to administer the maintenance of standards around the globe. The conference did not concern itself with other units of measure. The conference had undertones of Franco-German political manoeuvring, particularly since the French had been humiliated by the Prussians during the war
16905-426: The field of metrology in close cooperation with universities, other research institutions, and industry. PTB employs approximately 1900 staff members. It has a total budget of approx. €183 million at its disposal; in 2012, approx. €15 million was, in addition, canvassed as third-party funds for research projects. The Units and Time Act entrusts PTB also especially with the dissemination of legal time in Germany. To have
17066-454: The flexing when taking measurements. Moreover, the new bar, rather than being exactly one metre in length was a little longer than one metre and had lines engraved on them that were exactly one metre apart. The London firm Johnson Matthey delivered 30 prototype metres and 40 prototype kilograms. At the first meeting of the CGPM in 1889 bar No. 6 and cylinder No. X were chosen by lot as
17227-403: The flow of goods and services between trading partners. A common measurement system and quality standards benefit consumer and producer; production at a common standard reduces cost and consumer risk, ensuring that the product meets consumer needs. Transaction costs are reduced through an increased economy of scale . Several studies have indicated that increased standardisation in measurement has
17388-407: The fundamental reference points for metrological traceability. In the area of measurement, BIPM has identified nine metrology areas, which are acoustics, electricity and magnetism, length, mass and related quantities, photometry and radiometry, ionizing radiation, time and frequency, thermometry, and chemistry. As of May 2019 no physical objects define the base units. The motivation in the change of
17549-411: The hierarchy of metrology: primary, secondary, and working standards. Primary standards (the highest quality) do not reference any other standards. Secondary standards are calibrated with reference to a primary standard. Working standards, used to calibrate (or check) measuring instruments or other material measures, are calibrated with respect to secondary standards. The hierarchy preserves the quality of
17710-524: The higher standards. An example of a standard would be gauge blocks for length. A gauge block is a block of metal or ceramic with two opposing faces ground precisely flat and parallel, a precise distance apart. The length of the path of light in vacuum during a time interval of 1/299,792,458 of a second is embodied in an artefact standard such as a gauge block; this gauge block is then a primary standard which can be used to calibrate secondary standards through mechanical comparators. Metrological traceability
17871-429: The human body is challenging, with poor repeatability and reproducibility , and advances in metrology help develop new techniques to improve health care and reduce costs. Environmental policy is based on research data, and accurate measurements are important for assessing climate change and environmental regulation. Aside from regulation, metrology is essential in supporting innovation, the ability to measure provides
18032-448: The ideology of National Socialism found its way into the PTR. The convinced advocate of a German Physics terminated diverse research projects on issues of modern physics to which he referred to as "Jewish", among them, in particular, works on quantum physics and on the theory of relativity . Stark also tried to enforce the " Führer principle " (Führerprinzip) at the PTR: in 1935, he dissolved
18193-419: The individual states. The International System of Units (SI) defines seven base units: length , mass , time , electric current , thermodynamic temperature , amount of substance , and luminous intensity . By convention, each of these units are considered to be mutually independent and can be constructed directly from their defining constants. All other SI units are constructed as products of powers of
18354-418: The initial batch of prototypes had been distributed; in 2012 it had a staff of over 70 people and an annual budget of over €10 million. The director of the BIPM is ex-officio a member of the CIPM and a member of all consultative committees. The original treaty was written in French and the authoritative language of all official documents is French. Communication between the BIPM and member states is, in
18515-418: The instrument history, manufacturer's specifications, or published information. Several international organizations maintain and standardise metrology. The Metre Convention created three main international organizations to facilitate standardisation of weights and measures. The first, the General Conference on Weights and Measures (CGPM), provided a forum for representatives of member states. The second,
18676-588: The international prototypes. This was agreed in principle by the International Electrotechnical Commission at its congress in Brussels in 1935 subject to the choice of the fourth unit being agreed with, amongst others, the appropriate consultative committee of the CIPM. In 1948, three years after the end of World War II and fifteen years after the 8th CGPM, the 9th CGPM was convened. In response to formal requests made by
18837-418: The international prototypes. The remainder were either kept as BIPM working copies or distributed by lot to member states as national prototypes. The prototype metre was retained as the international standard until 1960 when the metre was redefined in terms of the wavelength of the orange-red line of krypton-86 . The current definition of the metre is "the length of the path travelled by light in vacuum during
18998-480: The invitations and in 1875 scientists from thirty European and American countries met in Paris. This same year, the International Association of Geodesy held its General Conference in Paris and decided the creation of an international geodetic standard for baselines' measurement, calibrated against the metre. The principal tasks facing the delegates at the 1875 conference was the replacement of
19159-498: The largest national metrology institutes in the world. As such, it is in charge of the realization and dissemination of the physical units and promotes the worldwide uniformity of metrology. The PTB magazine maßstäbe , which is published approximately once a year, can be subscribed to free of charge or it can be downloaded from the Internet pages of PTB. It contains articles about the quantities of physics. These articles are intended to be generally understandable and informative for
19320-606: The last GDR years; the name already indicates that this office of the GDR had more extensive tasks than PTB in the Federal Republic of Germany (FRG), namely additional tasks in the field of standardization and quality assurance and in the area of activity of the Bundesanstalt für Materialforschung und -prüfung (BAM). The young PTB grew rapidly in the years after its founding – both in terms of staff and in terms of financial resources. Not only its scientific metrological profile
19481-857: The latter is located in the Willy Wien Laboratory. PTB is headed by the Presidential Board in Braunschweig, which is composed of the President, the Vice-President and a further member. Another executive committee is the Directors' Conference, with the Presidential Board and the Heads of the Divisions as members. PTB is advised by the Kuratorium (PTB's Advisory Board), which is composed of representatives from science,
19642-409: The mass of the international prototype of the kilogram were detected. At the 21st meeting of the CGPM (1999), national laboratories were urged to investigate ways of breaking the link between the kilogram and a specific artefact. Independently of this drift having been identified, the Avogadro project and development of the Kibble (or watt) balance promised methods of indirectly measuring mass with
19803-411: The mathematician and physicist Wilhelm Foerster . Prussia, however, initially rejected their demands. Not until some years later were Werner von Siemens and Hermann von Helmholtz, the "founding fathers" of the PTR, able to make their vision – the establishment of a research institute which was to link scientific, technical and industrial interests in an optimal way – come true. Finally, on 28 March 1887,
19964-418: The measurement value and uncertainty of the device that is being calibrated (the comparator) and create a traceability link to the measurement standard. The four primary reasons for calibrations are to provide traceability, to ensure that the instrument (or standard) is consistent with other measurements, to determine accuracy, and to establish reliability. Traceability works as a pyramid, at the top level there
20125-609: The measurement. Recognition of the metrological competence in industry can be achieved through mutual recognition agreements, accreditation, or peer review. Industrial metrology is important to a country's economic and industrial development, and the condition of a country's industrial-metrology program can indicate its economic status. Legal metrology "concerns activities which result from statutory requirements and concern measurement, units of measurement , measuring instruments and methods of measurement and which are performed by competent bodies". Such statutory requirements may arise from
20286-447: The metre, kilogram, second and one electrical unit ( ampere , volt or ohm ). In 1921 the convention was extended to permit the promotion of standards relating to any physical quantity which greatly increased the scope of the CIPM's remit and implicitly giving it freedom to exploit Giorgi's proposals. The 8th CGPM (1933) resolved to work with other international bodies to agree to standards for electrical units that could be related back to
20447-674: The metre. Between 1840 and 1870, a number of countries definitively adopted the metric system as their system of measure including France, Spain, many South American republics and many of the Italian and German states (the Netherlands had adopted the system in 1817). In 1863, the International Postal Union used grams to express permitted weights of letters. In 1852 the Spanish Government was urged by
20608-621: The metric system between 1795 and 1875; to ensure conformity between the countries, the Bureau International des Poids et Mesures (BIPM) was established by the Metre Convention . This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960. Metrology is divided into three basic overlapping activities: These overlapping activities are used in varying degrees by
20769-404: The need for protection of health, public safety, the environment, enabling taxation, protection of consumers and fair trade. The International Organization for Legal Metrology ( OIML ) was established to assist in harmonising regulations across national boundaries to ensure that legal requirements do not inhibit trade. This harmonisation ensures that certification of measuring devices in one country
20930-429: The now historical international prototype of the kilogram and provides metrology services for Member States and hosts formal meetings. It also has custody of the former international prototype of the metre which was retired in 1960. Over the years the various prototypes of the metre and of the kilogram were returned to the BIPM laboratories for recalibration services. Initially it had a staff of 9, falling to 4 once
21091-716: The primary baseline of the U.S. Survey of the Coast, which was renamed the United States Coast Survey in 1836 and the United States Coast and Geodetic Survey in 1878, was measured in 1834 at Fire Island using four two-metre iron bars constructed after Hassler's specification in the United Kingdom and brought back to the United States in 1815. All distances measured by the Survey of the Coast, Coast Survey, and Coast and Geodetic Survey were referred to
21252-529: The process. This process was formalized by the British Government and in 1979 as the quality control standard BS 5750 . In 1987 BS 5750 was adopted by ISO as the basis for ISO 9000 . ISO 9000 is a general purpose quality control standard which works in conjunction industry-specific standards: for example ISO 15195:2003 which gives the specific requirements for reference measurement laboratories in laboratory medicine. International trade
21413-408: The realisation of the unit definition is propagated down through the pyramid. The traceability chain works upwards from the bottom of the pyramid, where measurements done by industry and testing laboratories can be directly related to the unit definition at the top through the traceability chain created by calibration. Measurement uncertainty is a value associated with a measurement which expresses
21574-401: The realisation of these units of measurement in practice, and the application of chains of traceability (linking measurements to reference standards). These concepts apply in different degrees to metrology's three main fields: scientific metrology; applied, technical or industrial metrology, and legal metrology. Scientific metrology is concerned with the establishment of units of measurement,
21735-788: The realization and dissemination of the units to PTB. All legally relevant aspects regarding the units as well as PTB’s responsibilities have been combined in this Act. Previously, all questions regarding the units as well as the role of PTB had been distributed among three laws: the Units Act, the Time Act, and the Verification Act. PTB consists of nine technical-scientific divisions (two of them in Berlin), which are subdivided into approx. 60 departments. These again are subdivided into more than 200 working groups. PTB's tasks are as follows:
21896-453: The recommended symbols for the most important MKS and CGS units of measure and for the first time the CGPM made recommendations concerning derived units. The CIPM's draft proposal, which was an extensive revision and simplification of the metric unit definitions, symbols and terminology based on the MKS system of units, was put to the 10th CGPM in 1954. In the proposal the CIPM recommended that
22057-495: The reproducibility of the metre and the kilogram and the threat that a rival standard might be set up, Napoleon III invited scientists from all the world's nations to attend a conference in Paris. In July 1870, two weeks before the conference was due to start, the Franco-Prussian War broke out. Although the delegates did meet (without a German delegation), it was agreed that the conference should be recalled once all
22218-474: The same as when they adopted in 1799. Prior to the 1870 conference, French politicians had feared that the world community might reject the existing metre as it was 0.03% (300 μm) shorter than its design length, ordering a new meridional measurement. They were eventually reassured when the German-born Swiss delegate Adolphe Hirsch said "no serious scientist would in our day and age contemplate
22379-436: The seven base units. Since the base units are the reference points for all measurements taken in SI units, if the reference value changed all prior measurements would be incorrect. Before 2019, if a piece of the international prototype of the kilogram had been snapped off, it would have still been defined as a kilogram; all previous measured values of a kilogram would be heavier. The importance of reproducible SI units has led
22540-411: The spread of possible values associated with the measurand —a quantitative expression of the doubt existing in the measurement. There are two components to the uncertainty of a measurement: the width of the uncertainty interval and the confidence level. The uncertainty interval is a range of values that the measurement value expected to fall within, while the confidence level is how likely the true value
22701-413: The standardization of weights and measures around the world. The first, the CGPM provides a forum for representative of member states, the second, the CIPM is an advisory committee of metrologists of high standing. The Secretariat or Headquarters provides appropriate meeting and laboratory facilities in support of the CGPM and CIPM. The structure may be compared to a corporation , the CIPM is analogous to
22862-414: The suitability of measurement instruments, their calibration and quality control. Producing good measurements is important in industry as it has an impact on the value and quality of the end product, and a 10–15% impact on production costs. Although the emphasis in this area of metrology is on the measurements themselves, traceability of the measuring- device calibration is necessary to ensure confidence in
23023-558: The tasks of PTB’s "Metrological Information Technology" Department – in accordance with the German Gambling Ordinance ( § 11 ff. SpielV) – is to grant type approvals for gaming machines which offer the possibility to make winnings. Also, according to the Federal Ordinance on Voting Machines, PTB is in charge of the type approval of voting computers. This is, however, moot as, in a judgment of 3 March 2009,
23184-562: The three basic sub-fields of metrology: In each country, a national measurement system (NMS) exists as a network of laboratories, calibration facilities and accreditation bodies which implement and maintain its metrology infrastructure. The NMS affects how measurements are made in a country and their recognition by the international community, which has a wide-ranging impact in its society (including economics, energy, environment, health, manufacturing, industry and consumer confidence). The effects of metrology on trade and economy are some of
23345-443: The time of the revolution, the number of units of measure had grown to the extent that it was almost impossible to keep track of them. In England in 1215, clause 35 of Magna Carta required that the same standards of measurement be applied throughout the realm. The wording of the clause emphasized that "There is to be a single measure ... throughout our realm". Five centuries later, when in 1707 England and Scotland were united into
23506-489: The upcoming electrical industry under the direction of the inventor and industrialist Werner von Siemens . In contrast to the units of length and weight, no recognized methods and standards existed at that time in the field of electrical metrology. The lack of reliable and verifiable measurement methods for the realization of electrical (and other) measurement units was a pressing scientific and economic problem. In 1872, some Prussian natural scientists joined forces and demanded
23667-726: The well-meaning support of the British Military Government, parts of the old Reichsanstalt were established in Braunschweig. The idea for this re-founding had been developed by the former PTR advisor for theoretical physics, Max von Laue, already during his internment in Farm Hall . In 1947, he succeeded in convincing the British authorities to make the former Luftfahrtforschungsanstalt (Aeronautical Research Institute) in Völkenrode near Braunschweig available to
23828-476: The width of his hand, and replica standards were given to builders. The success of a standardised length for the building of the pyramids is indicated by the lengths of their bases differing by no more than 0.05 per cent. In China weights and measures had a semi religious meaning as it was used in the various crafts by the Artificers and in ritual utensils and is mentioned in the book of rites along with
23989-458: The world and the BIPM, in terms of the mandate given to it under the Metre Convention, coordinates the various atomic clocks. After 1960, when the definition of the metre was linked to a particular wavelength of light rather than the international prototype of the metre, the only unit of measure that remained dependent on a particular artefact was the kilogram. Over the years, small drifts which could be as high as 20 × 10 kilograms per annum in
24150-410: The world. The chain of traceability allows any measurement to be referenced to higher levels of measurements back to the original definition of the unit. Traceability is obtained directly through calibration , establishing the relationship between an indication on a standard traceable measuring instrument and the value of the comparator (or comparative measuring instrument). The process will determine
24311-427: The ″Bundesamt für Strahlenschutz″ ( Federal Office for Radiation Protection ) after same had been newly established. Today, PTB’s Division 6 deals with ionizing radiation in general. This also includes a highly sensitive trace survey station for radionuclides which has been measuring radioactive substances in ground-level air for more than 50 years. The " Wende " ("political change") in Germany in 1990 also led to
24472-455: Was all but destroyed during the Franco-Prussian War (1870–1) and the Pavillon badly damaged. The Pavillon has been fully restored and, as headquarters of an intergovernmental organization enjoys privileges and immunities. The science of metrology has progressed vastly since 1875. In particular the treaty was amended in 1921 with the result that many other international organizations have
24633-482: Was also the official bulletin in which the type approvals granted by PTB as well as the tests and conformity assessments carried out by PTB were published in a section of its own [named "Amtliche Bekanntmachungen" ("Official Notes")]. With the new Measures and Verification Act which has been in force since 1 January 2015 and with the new Measures and Verification Ordinance, there is no longer a legal basis for these notices. From 2015 onwards, "PTB-Mitteilungen" is, therefore,
24794-588: Was created in 2002 through a Declaration of Cooperation between the International Committee of Weights and Measures (CIPM), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), and the International Laboratory Accreditation Cooperation (ILAC). The joint committee provides a forum for the harmonization of standards of the various participants. With the advent of
24955-500: Was extended, but also its palette of services rendered to industry, in particular in the form of calibrations of measuring instruments. In the 1970s, this led to the founding of the Deutscher Kalibrierdienst (German Calibration Service), which delegated service tasks to accredited, privately run laboratories and allowed PTB to concentrate itself on more demanding measurement tasks. From 1967 to 1995, PTB operated
25116-635: Was integrated into this institute as ꞋꞋBerlin InstituteꞋꞋ while respecting the four-power status of Berlin. In the German Democratic Republic (GDR), the Deutsches Amt für Maß und Gewicht (DAMG) had established itself with its principle seat in Berlin. After several renamings, this institute was designated Amt für Standardisierung, Meßwesen und Warenprüfung (Office for Standardization, Metrology and Quality Control – ASMW) during
25277-416: Was named the International System of Units ( Système international d'unités , abbreviated SI). The Metre Convention provides that only nations can be members of the BIPM. In 1999, the CGPM created in the status of associate, to allow non-member states and economic entities to participate in some activities of the BIPM through their national metrology institutes (NMIs). As of 13 January 2020 ,
25438-439: Was not only to investigate general – but mainly also military – fields of application. This included, among other things, the acoustic finding of artillery, the military utilization of ultrasound and the development of decoding procedures. In addition, researchers of PTR developed acoustic mines and a steering system for torpedoes which orientated itself on the sound field of traveling ships. Due to its classical metrological tasks,
25599-406: Was signed in Paris on 20 May 1875 by representatives of 17 nations: Argentina, Austria-Hungary, Belgium, Brazil, Denmark, France, Germany, Italy, Peru, Portugal, Russia, Spain, Sweden and Norway, Switzerland, Ottoman Empire, United States of America, and Venezuela. The treaty created the International Bureau of Weights and Measures (BIPM), an intergovernmental organization , under the authority of
25760-464: Was the main reference for measuring all geodetic bases in France and whose length was 3.8980732 metres. In 1867 at the second General Conference of the International Association of Geodesy (German: Europäische Gradmessung ) held in Berlin , the question of international standard of length was discussed in order to combine the measurements made in different countries to determine the size and shape of
25921-509: Was to create international standards for units of measurement and relate them to national standards to ensure conformity, its scope has broadened to include electrical and photometric units and ionizing radiation measurement standards. The metric system was modernised in 1960 with the creation of the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures ( French : Conference Generale des Poids et Mesures , or CGPM). Metrology
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