814:, 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 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 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 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.
785:(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 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 the higher standards. An example of a standard would be
1056:
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 is compatible with the certification process in other participating countries, allowing the trade of the measuring devices and the products that rely on them.
257:
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 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.
1163:
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 a lead NMI and several decentralised institutes specialising in specific national standards. Some examples of NMI's are the
1155:
799:
248:
human activity. Metrology is a wide reaching field, but can be summarized through three basic activities: the definition of internationally accepted units of measurement, 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.
1068:(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 a conference in 1977 to develop international cooperation for accredited testing and calibration results to facilitate trade. In 2000, 36 members signed the ILAC
1072:(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 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.
948:, 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 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
829:—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 is to fall within the uncertainty interval. Uncertainty is generally expressed as follows:
972:, 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 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
986:
40:
750:
2085:
264:, 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 a kilogram without an artefact the value of the
306:) 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 is compatible with another country's certification process, allowing the trade of the measuring devices and the products that rely on them.
903:= 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 the instrument history, manufacturer's specifications, or published information.
1146:
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 the CIPM MRA, consisting of 58 member states, 40 associate states, and 4 international organizations.
302:, measuring instruments and methods of measurement and which are performed by competent bodies". Such statutory requirements may arise from the need for protection of health, public safety, the environment, enabling taxation, protection of consumers and fair trade. The International Organization for Legal Metrology (
1232:. 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.
807:
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 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.
1145:
A national measurement system (NMS) is a network of laboratories, calibration facilities and accreditation bodies which implement and maintain a country's measurement infrastructure. The NMS sets measurement standards, ensuring the accuracy, consistency, comparability, and reliability of measurements
134:
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,
789:
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
621:
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;
289:
calibration is necessary to ensure confidence in 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
1223:
and promote 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
927:
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, the International Committee for Weights and Measures (CIPM), was an advisory committee of metrologists of high
284:
Applied, technical or industrial metrology is concerned with the application of measurement to manufacturing and other processes and their use in society, ensuring the suitability of measurement instruments, their calibration and quality control. Producing good measurements is important in industry
1255:
and environmental regulation. Aside from regulation, metrology is essential in supporting innovation, the ability to measure provides 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
976:
to discuss reports from 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
256:
Scientific metrology is concerned with the establishment of units of measurement, 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
247:
Metrology 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
1218:
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
1162:
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 a
179:
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
1055:
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 a mutual
806:
Metrological traceability 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
1196:
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, a country's accreditation body must comply with international requirements and is
1037:
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 the costs of discrepancies and
1187:
Calibration laboratories are generally responsible for calibrations of industrial instrumentation. Calibration laboratories are accredited and provide calibration services to industry firms, which provides a traceability link back to the national metrology institute. Since the calibration
1136:
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.
1009:, 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
886:
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
629:
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
135:
manufacturing, industry and consumer confidence). The effects of metrology on trade and economy are some of the easiest-observed societal impacts. To facilitate fair trade, there must be an agreed-upon system of measurement.
367:. 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 the seven base units.
1201:
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
285:
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-
1689:... any application of metrology may fall under the scope of legal metrology if regulations are applicable to all measuring methods and instruments, and in particular if quality control is supervised by the state.
1105:
1827:
215:. Although the BIPM's original mission 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
1251:, 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
2169:
157:. The cubit was decreed to be the length of the Pharaoh's forearm plus the width of his hand, and replica standards were given to builders. The success of a standardised length for the building of
78:
in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the
1750:
180:
were common, comparability was difficult since many local systems were incompatible. England established the Assize of
Measures to create standards for length measurements in 1196, and the 1215
2554:
741:)), subject to correction to their present definitions. The new definitions aim to improve the SI without changing the size of any units, thus ensuring continuity with existing measurements.
622:
all previous measured values of a kilogram would be heavier. The importance of reproducible SI units has led the BIPM to complete the task of defining all SI base units in terms of
199:
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
1627:
149:
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
1065:
1667:
1478:
1117:
1818:
961:
949:
862:
74:'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
1123:
3487:
1219:
between countries, there must be an agreed-upon system of measurement. Accurate measurement and regulation of water, fuel, food, and electricity are critical for
1164:
1111:
753:
Computer-generated image realising the international prototype of the kilogram (IPK), made from an alloy of 90-per cent platinum and 10-per cent iridium by weight
319:
44:
1176:
1022:
2520:
3461:
2374:
994:
200:
80:
2009:"New measurement will help redefine international unit of mass: Ahead of July 1 deadline, team makes its most precise measurement yet of Planck's constant"
1203:
2604:
2162:
1920:
937:
228:
93:
59:. With this instrument, the measurement of mass is no longer dependent on a defined mass standard and is instead dependent on natural physical constants.
1743:
1099:
260:
As of May 2019 no physical objects define the base units. The motivation in the change of the base units is to make the entire system derivable from
2545:
1528:
928:
standing. The third, the
International Bureau of Weights and Measures (BIPM), provided secretarial and laboratory facilities for the CGPM and CIPM.
1081:
1006:
765:(VIM): a physical realisation of the unit from its definition, a highly-reproducible measurement as a reproduction of the definition (such as the
762:
3126:
1681:
1492:
191:. With a political motivation to harmonise units throughout France, a length standard based on a natural source was proposed. In March 1791, the
3124:
JCGM 100:2008. Evaluation of measurement data – Guide to the expression of uncertainty in measurement, Joint
Committee for Guides in Metrology.
2477:
2378:
1560:
1295:
2813:
2411:
2256:
2145:
2079:
1900:
1675:
1637:
1486:
1307:
1172:
3205:
1265:
1207:
3422:
Rodrigues Filho, Bruno A.; Gonçalves, Rodrigo F. (June 2015). "Legal metrology, the economy and society: A systematic literature review".
3283:
1782:
1197:
generally the product of international and regional cooperation. A laboratory is evaluated according to international standards such as
2787:
1168:
1643:
2874:
2704:
2069:
3154:
315:
2965:
2274:
2107:
2907:
1034:
70:. It establishes a common understanding of units, crucial in linking human activities. Modern metrology has its roots in the
3067:
891:= 2 generally indicates a 95% confidence that the measured value will fall inside the uncertainty interval. Other values of
1867:
318:(EFTA) member states. In the United States legal metrology is under the authority of the Office of Weights and Measures of
2202:
790:
gauge block is then a primary standard which can be used to calibrate secondary standards through mechanical comparators.
336:
224:
89:
1946:
1404:
123:
Applied, technical or industrial metrology—the application of measurement to manufacturing and other processes in society
3183:
2301:
1069:
126:
Legal metrology, covering the regulation and statutory requirements for measuring instruments and methods of measurement
3483:
2765:
2655:
2513:
2848:
1042:
Recommendations: Model regulations to establish metrological characteristics and conformity of measuring instruments
2034:
1593:
924:
657:
276:, has produced a value of Planck constant with low enough uncertainty to allow for a redefinition of the kilogram.
3457:
2338:
356:
2633:
2585:
2425:
2309:
1916:
761:
of a unit of measure is its conversion into reality. Three possible methods of realisation are defined by the
1972:
604:
The luminous intensity, in a given direction, of a source emitting monochromatic radiation of a frequency of
2343:
822:
758:
450:
825:
is a value associated with a measurement which expresses the spread of possible values associated with the
1271:
1229:
1154:
144:
3045:
1521:
3517:
Presentation about
Product Quality planning that includes a typical industry "Dimensional Control Plan"
2984:
2926:
1322:
1277:
1228:. Several studies have indicated that increased standardisation in measurement has a positive impact on
1188:
laboratories are accredited, they give companies a traceability link to national metrology standards.
298:
Legal metrology "concerns activities which result from statutory requirements and concern measurement,
164:
In China weights and measures had a semi religious meaning as it was used in the various crafts by the
3123:
1708:
1658:
1469:
113:
These overlapping activities are used in varying degrees by the three basic sub-fields of metrology:
3546:
3431:
2243:
2042:
1890:
1301:
782:
286:
158:
118:
2486:
2365:
1564:
1243:, by improving their efficiency and reliability. Measuring the human body is challenging, with poor
401:
The duration of 9192631770 periods of the radiation corresponding to the transition between the two
3257:
2820:
2450:
1358:
1220:
766:
410:
402:
360:
299:
216:
3231:
1256:
demonstrated, and shared, measurement standards allow new ideas to be explored and expanded upon.
1038:
measurement duplication. The OIML publishes a number of international reports in four categories:
3541:
3209:
2681:
2008:
1316:
1289:
1225:
667:
530:
364:
261:
220:
1892:
Delphi
Collected Works of Confucius - Four Books and Five Classics of Confucianism (Illustrated)
268:
must be known to twenty parts per billion. Scientific metrology, through the development of the
2596:
2407:
2252:
2141:
2075:
1896:
1671:
1633:
1482:
1364:
1010:
835:
723:
677:
623:
578:
494:
188:
173:
71:
2351:
1778:
3439:
2791:
2739:
920:
702:
352:
273:
212:
85:
52:
2690:
2519:. World Meteorological Organization Commission for Instruments and Methods of Observation.
2367:
International vocabulary of metrology—Basic and general concepts and associated terms (VIM)
1235:
Legal metrology has reduced accidental deaths and injuries with measuring devices, such as
952:(CIPM) had proposed earlier that year. The new definitions came into force on 20 May 2019.
3130:
2997:
2939:
2735:
1993:
1343:
1248:
1026:
998:
965:
941:
647:
454:
265:
232:
204:
130:
In each country, a national measurement system (NMS) exists as a network of laboratories,
2878:
2713:
2595:(Issue 2 ed.). Teddington, Middlesex, United Kingdom: National Physical Laboratory.
223:
measurement standards. The metric system was modernised in 1960 with the creation of the
3435:
3014:
290:
condition of a country's industrial-metrology program can indicate its economic status.
2479:
International vocabulary of metrology – basic and general concepts and associated terms
1349:
1252:
1090:
International vocabulary of metrology – basic and general concepts and associated terms
1051:
Basic publications: Definitions of the operating rules of the OIML structure and system
713:
311:
269:
3443:
310:
was established in 1990 to promote cooperation in the field of legal metrology in the
39:
3535:
1244:
1198:
196:
169:
75:
3145:
798:
161:
is indicated by the lengths of their bases differing by no more than 0.05 per cent.
3309:
2964:. OIML B 15 (2011 (E) ed.). Paris: Bureau International de MĂ©trologie LĂ©gale.
2958:
2900:
2332:
2278:
2116:
1240:
895:
can be used to indicate a greater or lower confidence on the interval, for example
786:
406:
2485:(3 ed.). Joint Committee on Guides for Metrology (JCGM). 2008. Archived from
3511:
3074:
2547:
Guide to the Evaluation of Measurement Uncertainty for Quantitative Test Results
1863:
1331:
811:
643:
561:
181:
165:
131:
67:
31:
2194:
1005:, or BIPM) is an organisation based in Sèvres, France which has custody of the
1942:
1412:
1337:
3354:"Creating impact from science and engineering – National Physical Laboratory"
3179:
2600:
1409:
Celebration of the signing of the Metre Convention, World Metrology Day 2004"
109:
Traceability—linking measurements made in practice to the reference standards
2377:
on behalf of the Joint Committee for Guides in Metrology. 2012. p. 46.
1236:
826:
613:
17:
2706:
BIPM statement: Information for users about the proposed revision of the SI
1561:"History of measurement – from metre to International System of Units (SI)"
973:
2901:"Convention establishing an International Organisation of Legal Metrology"
2761:
2659:
1384:
Equivalent to standard deviation if the uncertainty distribution is normal
2852:
1826:. Australian Government, Department of Industry, Innovation and Science.
1367: – Application of quantum entanglement to high-precision measurement
631:
441:
117:
Scientific or fundamental metrology, concerned with the establishment of
2251:(9th ed.), International Bureau of Weights and Measures, Dec 2022,
1589:
1352: – Specifying measures of time-measurement in clear reference units
1084:(JCGM) is a committee which created and maintains two metrology guides:
985:
911:
Several international organizations maintain and standardise metrology.
749:
698:
596:
154:
56:
3310:"Measurement science and standards – National Research Council Canada"
1106:
International Federation of Clinical Chemistry and Laboratory Medicine
2629:
690:
639:
635:
577:
elementary entities. This number is the fixed numerical value of the
529:
Defined (as of 2019) by "... taking the fixed numerical value of the
521:
493:
Defined (as of 2019) by "... taking the fixed numerical value of the
485:
430:
393:
340:
307:
48:
3375:
3073:. International Laboratory Accreditation Cooperation. Archived from
1310: – Committee under the chairmanship of the director of the BIPM
3102:
1298: – System for defining and representing engineering tolerances
1092:(VIM). The JCGM is a collaboration of eight partner organisations:
3512:
Measurement Uncertainties in Science and Technology, Springer 2005
2751:
Convention of the Metre (1875), Appendix 1 (Regulation), Article 8
1968:
1153:
984:
797:
748:
694:
421:
192:
150:
38:
3208:. National Metrology Center (NMC). 23 August 2013. Archived from
2790:. Bureau International des Poids et Mesures. 2011. Archived from
2658:. Bureau International des Poids et Mesures. 2011. Archived from
1657:
Collège français de métrologie (2006). Placko, Dominique (ed.).
1468:
Collège français de métrologie (2006). Placko, Dominique (ed.).
773:), and the use of a material object as the measurement standard.
3526:
3484:"Metrology for Society's Challenges – Metrology for Environment"
3103:"ILAC's Role International Laboratory Accreditation Cooperation"
2306:
Keynote address, ITS (Ninth International Temperature Symposium)
1340: – Journal dealing with the scientific aspects of metrology
348:
344:
303:
1319: – Ways in which length, distance or range can be measured
99:
Metrology is divided into three basic overlapping activities:
3397:
3041:
2906:. 2000 (E). Paris: Bureau International de MĂ©trologie LĂ©gale.
770:
3331:
3153:. Joint Committee for Guides in Metrology. 10 December 2009.
1699:
1697:
977:
role in establishing the convention) always having one seat.
612:
with a radiant intensity in that direction of 1/683 watt per
2074:(Online-Ausg. ed.). Oxford: Routledge. pp. 12–13.
3521:
3458:"Metrology for Society's Challenges – Metrology for Health"
3260:. Bureau International des Poids et Mesures. Archived from
2277:. Bureau International des Poids et Mesures. Archived from
1704:
195:
was defined. This led to the creation of the decimal-based
3516:
1632:(2nd ed.). Springer. 1.2.2 Categories of Metrology.
1132:
International Laboratory Accreditation Cooperation (ILAC)
1013:
of the CIPM and a member of all consultative committees.
184:
included a section for the measurement of wine and beer.
106:
The realisation of these units of measurement in practice
3261:
2762:"CIPM: International Committee for Weights and Measures"
1817:
Robertson, Kristel; Swanepoel, Jan A. (September 2015).
701:
have previously been defined by physical constants (the
3353:
2199:
The NIST Reference on Constants, Units, and Uncertainty
1354:
Pages displaying short descriptions of redirect targets
3147:
Charter Joint Committee for Guides in Metrology (JCGM)
3044:. International Laboratory Accreditation Cooperation.
1334: – Conversion to the metric system of measurement
646:
are defined by setting exact numerical values for the
2875:"Criteria for membership of a Consultative Committee"
1086:
Guide to the expression of uncertainty in measurement
838:
2109:
International Vocabulary of Terms in Legal Metrology
1327:
Pages displaying wikidata descriptions as a fallback
1312:
Pages displaying wikidata descriptions as a fallback
1282:
Pages displaying wikidata descriptions as a fallback
1129:
International Organization of Legal Metrology (OIML)
2764:. Bureau International des Poids et Mesures. 2011.
1292: – Science of measurement applied to forensics
1096:
International Bureau of Weights and Measures (BIPM)
1045:
Informative documents: To harmonise legal metrology
2586:"A Beginner's Guide to Uncertainty of Measurement"
2553:. Paris, France: EUROLAB. August 2006. p. 8.
2331:
2201:. National Institute of Standards and Technology.
2138:Measurement, instrumentation, and sensors handbook
1285:Pages displaying short descriptions with no spaces
1066:International Laboratory Accreditation Cooperation
1060:International Laboratory Accreditation Cooperation
856:
453:) by "... taking the fixed numerical value of the
433:during a time interval of 1/299792458 of a second
3417:
3415:
2404:Manufacturing Processes and Systems (9th Edition)
2238:
2236:
2234:
2232:
2230:
2228:
2226:
2224:
2222:
2220:
1668:International Society for Technology in Education
1118:International Union of Pure and Applied Chemistry
1048:Guidelines for the application of legal metrology
3180:"Joint Committee for Guides in Metrology (JCGM)"
2691:International Committee for Weights and Measures
1866:. Measurement Science Conference. 17 June 2016.
1555:
1553:
1551:
1549:
1031:Organisation Internationale de MĂ©trologie LĂ©gale
962:International Committee for Weights and Measures
956:International Committee for Weights and Measures
950:International Committee for Weights and Measures
509:when expressed in the unit C, which is equal to
3140:
3138:
2140:(Second ed.). Boca Raton: CRC Press, Inc.
1124:International Union of Pure and Applied Physics
429:The length of the path travelled by light in a
168:and in ritual utensils and is mentioned in the
2593:Technical Review- National Physical Laboratory
2115:. Paris: OIML. 2000. p. 7. Archived from
1858:
1856:
1854:
1852:
1850:
1848:
1274: – Characterizations of measurement error
1165:National Institute of Standards and Technology
1112:International Organization for Standardization
320:National Institute of Standards and Technology
3522:Training in Metrology in Chemistry (TrainMiC)
3182:. Bureau International des Poids et Mesures.
2632:. Bureau International des Poids et Mesures.
1812:
1810:
1808:
1806:
1804:
1802:
1800:
1592:. Bureau International des Poids et Mesures.
1177:National Physical Laboratory (United Kingdom)
1023:International Organization of Legal Metrology
1017:International Organization of Legal Metrology
227:(SI) as a result of a resolution at the 11th
92:(SI) as a result of a resolution at the 11th
8:
3356:. National Physical Laboratory. 17 June 2017
2656:"General Conference on Weights and Measures"
2375:International Bureau of Weights and Measures
1626:Czichos, Horst; Smith, Leslie, eds. (2011).
995:International Bureau of Weights and Measures
981:International Bureau of Weights and Measures
201:International Bureau of Weights and Measures
3284:"International Legal Organizational Primer"
3238:. Bureau International des Poids et Mesures
3097:
3095:
2953:
2951:
2949:
2514:"Metrological Traceability for Meteorology"
1660:Metrology in Industry – The Key for Quality
1471:Metrology in Industry – The Key for Quality
1204:National Association of Testing Authorities
322:(NIST), enforced by the individual states.
3009:
3007:
2738:. The day is the 144th anniversary of the
2131:
2129:
2071:Basic Metrology for ISO 9000 Certification
1629:Springer Handbook of Metrology and Testing
938:General Conference on Weights and Measures
932:General Conference on Weights and Measures
810:Traceability is obtained directly through
280:Applied, technical or industrial metrology
229:General Conference on Weights and Measures
94:General Conference on Weights and Measures
27:Science of measurement and its application
3068:"The ILAC Mutual Recognition Arrangement"
2849:"International Prototype of the Kilogram"
1563:. La metrologie francaise. Archived from
1158:Overview of a national measurement system
1100:International Electrotechnical Commission
1003:Bureau international des poids et mesures
970:Comité international des poids et mesures
837:
209:Bureau International des Poids et Mesures
81:Bureau International des Poids et Mesures
47:Kibble balance, which is used to measure
2579:
2577:
2575:
2269:
2267:
2063:
2061:
2059:
1670:(ISTE). 2.4.1 Scope of legal metrology.
1584:
1582:
1346: – Approach to industrial metrology
946:Conférence générale des poids et mesures
369:
237:Conference Generale des Poids et Mesures
3036:
3034:
3032:
1590:"Resolution 12 of the 11th CGPM (1960)"
1515:
1513:
1511:
1509:
1507:
1505:
1396:
1377:
1082:Joint Committee for Guides in Metrology
1076:Joint Committee for Guides in Metrology
1007:international prototype of the kilogram
2993:
2982:
2935:
2924:
2843:
2841:
2768:from the original on 24 September 2012
2636:from the original on 26 September 2012
2508:
2506:
2472:
2470:
2468:
1773:
1771:
1463:
1461:
1459:
1457:
1455:
1453:
1451:
1449:
1361: – Annual celebration of SI units
1296:Geometric dimensioning and tolerancing
1210:are examples of accreditation bodies.
588:, when expressed in the unit mol ..."
187:Modern metrology has its roots in the
103:The definition of units of measurement
3312:. National Research Council of Canada
2788:"Criteria for membership of the CIPM"
2736:"Decision CIPM/105-13 (October 2016)"
2560:from the original on 23 November 2016
2175:from the original on 28 February 2017
2088:from the original on 27 February 2018
2003:
2001:
1744:"The National Quality Infrastructure"
1738:
1736:
1734:
1732:
1730:
1728:
1726:
1711:from the original on 15 February 2017
1621:
1619:
1617:
1615:
1613:
1611:
1447:
1445:
1443:
1441:
1439:
1437:
1435:
1433:
1431:
1429:
1308:International vocabulary of metrology
1173:Physikalisch-Technische Bundesanstalt
763:international vocabulary of metrology
7:
3160:from the original on 24 October 2015
2971:from the original on 2 December 2016
2352:participating institution membership
2205:from the original on 19 January 2017
1779:"Metrology for Society's Challenges"
1304: – Study of measurement systems
1266:Outline of metrology and measurement
1208:United Kingdom Accreditation Service
2451:"e-Handbook of Statistical Methods"
2308:. Los Angeles: NIST. Archived from
2033:Crease, Robert P. (22 March 2011).
1994:Decision CIPM/105-13 (October 2016)
1522:"A Beginner's Guide to Measurement"
569:Contains (as of 2019) "... exactly
3490:from the original on 12 March 2017
3464:from the original on 12 March 2017
3258:"The BIPM key comparison database"
3048:from the original on 15 March 2017
2526:from the original on 17 March 2017
2384:from the original on 17 March 2017
2275:"On the future revision of the SI"
1969:"The BIPM key comparison database"
1949:from the original on 24 March 2017
1785:from the original on 12 March 2017
1749:. The Innovation Policy Platform.
1534:from the original on 29 March 2017
25:
3444:10.1016/j.measurement.2015.03.028
2913:from the original on 12 July 2014
2245:The International System of Units
1923:from the original on 1 March 2017
1870:from the original on 1 March 2017
1833:from the original on 7 March 2016
1756:from the original on 6 March 2017
1687:from the original on 2012-10-23.
1167:(NIST) in the United States, the
3527:Measurement Science in Chemistry
3186:from the original on 12 May 2017
2683:Proceedings of the 106th meeting
2300:KĂĽhne, Michael (22 March 2012).
1919:. National Physical Laboratory.
1707:. National Physical Laboratory.
1596:from the original on 14 May 2013
1527:. National Physical Laboratory.
1498:from the original on 2012-10-23.
2610:from the original on 3 May 2017
1975:from the original on 2013-09-28
1917:"History of Length Measurement"
339:(SI) defines seven base units:
316:European Free Trade Association
2814:"Mission, Role and Objectives"
2584:Bell, Stephanie (March 2001).
1035:intergovernmental organization
802:Metrology traceability pyramid
84:(BIPM) was established by the
1:
3206:"National Measurement System"
2693:. Sèvres. 16–20 October 2017.
2402:Phillip Ostwald,Jairo Muñoz,
1705:"National Measurement System"
882:is the uncertainty value and
878:is the measurement value and
337:International System of Units
225:International System of Units
211:, or BIPM) was formed by the
90:International System of Units
2406:John Wiley & Sons, 1997
1411:. BIPM. 2004. Archived from
1070:mutual recognition agreement
907:International infrastructure
794:Traceability and calibration
371:SI base units and standards
88:. This has evolved into the
925:international organizations
545:when expressed in the unit
469:when expressed in the unit
66:is the scientific study of
3563:
2426:"The Gauge Block Handbook"
2424:Doiron, Ted; Beers, John.
2068:de Silva, G. M. S (2012).
2035:"Metrology in the balance"
1820:The economics of metrology
1263:
1175:(PTB) in Germany, and the
658:elementary electric charge
142:
29:
2339:Oxford English Dictionary
1169:National Research Council
734:visible light radiation (
518:Thermodynamic temperature
357:thermodynamic temperature
2302:"Redefinition of the SI"
2163:"WELMEC An introduction"
1889:Confucius (2016-08-29).
1325: – academic journal
1183:Calibration laboratories
857:{\displaystyle Y=y\pm U}
30:Not to be confused with
2344:Oxford University Press
2136:Sharp, DeWayne (2014).
1141:National infrastructure
823:Measurement uncertainty
2992:Cite journal requires
2934:Cite journal requires
2877:. BIPM. Archived from
2851:. BIPM. Archived from
2819:. BIPM. Archived from
2630:"The Metre Convention"
2122:on September 28, 2007.
1864:"History of Metrology"
1280: – specialisation
1272:Accuracy and precision
1159:
1030:
1002:
990:
969:
945:
858:
803:
754:
236:
208:
153:was carved from black
145:History of measurement
60:
1323:Measurement (journal)
1278:Dimensional metrology
1206:in Australia and the
1171:(NRC) in Canada, the
1157:
988:
859:
801:
752:
689:), respectively. The
42:
3232:"BIPM – signatories"
2662:on 26 September 2012
2161:WELMEC Secretariat.
2043:Institute of Physics
1943:"What is metrology?"
1302:Historical metrology
1192:Accreditation bodies
1150:Metrology institutes
836:
745:Realisation of units
549:, which is equal to
473:, which is equal to
300:units of measurement
252:Scientific metrology
151:royal Egyptian cubit
119:units of measurement
3436:2015Meas...69..155R
2342:(Online ed.).
2281:on 15 February 2017
1895:. Delphi Classics.
1359:World Metrology Day
1221:consumer protection
923:created three main
767:quantum Hall effect
558:Amount of substance
372:
361:amount of substance
331:Definition of units
3264:on 29 January 2017
3129:2009-10-01 at the
3015:"MAA certificates"
1407:What is metrology?
1317:Length measurement
1290:Forensic metrology
1160:
1033:, or OIML), is an
991:
854:
804:
755:
668:Boltzmann constant
624:physical constants
593:Luminous intensity
531:Boltzmann constant
370:
365:luminous intensity
262:physical constants
221:ionizing radiation
61:
3376:"NATA – About Us"
3290:. 14 January 2010
2826:on 6 October 2016
2412:978-0-471-04741-4
2350:(Subscription or
2258:978-92-822-2272-0
2147:978-1-4398-4888-3
2081:978-1-136-42720-6
1902:978-1-78656-052-0
1677:978-1-905209-51-4
1639:978-3-642-16640-2
1520:Goldsmith, Mike.
1488:978-1-905209-51-4
1365:Quantum metrology
1011:ex officio member
866:Coverage factor:
724:luminous efficacy
678:Avogadro constant
619:
618:
579:Avogadro constant
495:elementary charge
189:French Revolution
176:and other tools.
174:steelyard balance
72:French Revolution
16:(Redirected from
3554:
3500:
3499:
3497:
3495:
3480:
3474:
3473:
3471:
3469:
3454:
3448:
3447:
3419:
3410:
3409:
3407:
3405:
3394:
3388:
3387:
3385:
3383:
3372:
3366:
3365:
3363:
3361:
3350:
3344:
3343:
3341:
3339:
3328:
3322:
3321:
3319:
3317:
3306:
3300:
3299:
3297:
3295:
3280:
3274:
3273:
3271:
3269:
3254:
3248:
3247:
3245:
3243:
3228:
3222:
3221:
3219:
3217:
3202:
3196:
3195:
3193:
3191:
3176:
3170:
3169:
3167:
3165:
3159:
3152:
3142:
3133:
3121:
3115:
3114:
3112:
3110:
3099:
3090:
3089:
3087:
3085:
3080:on 25 March 2017
3079:
3072:
3064:
3058:
3057:
3055:
3053:
3038:
3027:
3026:
3024:
3022:
3011:
3002:
3001:
2995:
2990:
2988:
2980:
2978:
2976:
2970:
2963:
2955:
2944:
2943:
2937:
2932:
2930:
2922:
2920:
2918:
2912:
2905:
2897:
2891:
2890:
2888:
2886:
2881:on 26 March 2018
2871:
2865:
2864:
2862:
2860:
2855:on 12 March 2020
2845:
2836:
2835:
2833:
2831:
2825:
2818:
2810:
2804:
2803:
2801:
2799:
2784:
2778:
2777:
2775:
2773:
2758:
2752:
2749:
2743:
2740:Metre Convention
2733:
2727:
2726:
2725:
2724:
2718:
2712:, archived from
2711:
2701:
2695:
2694:
2688:
2678:
2672:
2671:
2669:
2667:
2652:
2646:
2645:
2643:
2641:
2626:
2620:
2619:
2617:
2615:
2609:
2590:
2581:
2570:
2569:
2567:
2565:
2559:
2552:
2542:
2536:
2535:
2533:
2531:
2525:
2518:
2510:
2501:
2500:
2498:
2497:
2491:
2484:
2474:
2463:
2462:
2460:
2458:
2447:
2441:
2440:
2438:
2436:
2430:
2421:
2415:
2400:
2394:
2393:
2391:
2389:
2383:
2373:(3rd ed.).
2372:
2362:
2356:
2355:
2347:
2335:
2328:
2322:
2321:
2319:
2317:
2297:
2291:
2290:
2288:
2286:
2271:
2262:
2261:
2250:
2240:
2215:
2214:
2212:
2210:
2191:
2185:
2184:
2182:
2180:
2174:
2167:
2158:
2152:
2151:
2133:
2124:
2123:
2121:
2114:
2104:
2098:
2097:
2095:
2093:
2065:
2054:
2053:
2051:
2049:
2030:
2024:
2023:
2021:
2019:
2005:
1996:
1991:
1985:
1984:
1982:
1980:
1965:
1959:
1958:
1956:
1954:
1939:
1933:
1932:
1930:
1928:
1913:
1907:
1906:
1886:
1880:
1879:
1877:
1875:
1860:
1843:
1842:
1840:
1838:
1832:
1825:
1814:
1795:
1794:
1792:
1790:
1775:
1766:
1765:
1763:
1761:
1755:
1748:
1740:
1721:
1720:
1718:
1716:
1701:
1692:
1691:
1686:
1665:
1654:
1648:
1647:
1642:. Archived from
1623:
1606:
1605:
1603:
1601:
1586:
1577:
1576:
1574:
1572:
1567:on 25 April 2011
1557:
1544:
1543:
1541:
1539:
1533:
1526:
1517:
1500:
1499:
1497:
1476:
1465:
1424:
1423:
1421:
1420:
1401:
1385:
1382:
1355:
1328:
1313:
1286:
1283:
1226:economy of scale
921:Metre Convention
915:Metre Convention
863:
861:
860:
855:
733:
731:
720:
703:caesium standard
688:
674:
664:
654:
611:
609:
576:
574:
552:
548:
544:
542:
512:
508:
506:
482:Electric current
476:
472:
468:
466:
373:
353:electric current
274:Avogadro project
213:Metre Convention
96:(CGPM) in 1960.
86:Metre Convention
53:electric current
21:
3562:
3561:
3557:
3556:
3555:
3553:
3552:
3551:
3532:
3531:
3508:
3503:
3493:
3491:
3482:
3481:
3477:
3467:
3465:
3456:
3455:
3451:
3421:
3420:
3413:
3403:
3401:
3396:
3395:
3391:
3381:
3379:
3374:
3373:
3369:
3359:
3357:
3352:
3351:
3347:
3337:
3335:
3330:
3329:
3325:
3315:
3313:
3308:
3307:
3303:
3293:
3291:
3282:
3281:
3277:
3267:
3265:
3256:
3255:
3251:
3241:
3239:
3230:
3229:
3225:
3215:
3213:
3212:on 6 March 2017
3204:
3203:
3199:
3189:
3187:
3178:
3177:
3173:
3163:
3161:
3157:
3150:
3144:
3143:
3136:
3131:Wayback Machine
3122:
3118:
3108:
3106:
3101:
3100:
3093:
3083:
3081:
3077:
3070:
3066:
3065:
3061:
3051:
3049:
3040:
3039:
3030:
3020:
3018:
3013:
3012:
3005:
2991:
2981:
2974:
2972:
2968:
2961:
2959:"OIML Strategy"
2957:
2956:
2947:
2933:
2923:
2916:
2914:
2910:
2903:
2899:
2898:
2894:
2884:
2882:
2873:
2872:
2868:
2858:
2856:
2847:
2846:
2839:
2829:
2827:
2823:
2816:
2812:
2811:
2807:
2797:
2795:
2786:
2785:
2781:
2771:
2769:
2760:
2759:
2755:
2750:
2746:
2734:
2730:
2722:
2720:
2716:
2709:
2703:
2702:
2698:
2686:
2680:
2679:
2675:
2665:
2663:
2654:
2653:
2649:
2639:
2637:
2628:
2627:
2623:
2613:
2611:
2607:
2588:
2583:
2582:
2573:
2563:
2561:
2557:
2550:
2544:
2543:
2539:
2529:
2527:
2523:
2516:
2512:
2511:
2504:
2495:
2493:
2489:
2482:
2476:
2475:
2466:
2456:
2454:
2453:. NIST/SEMATECH
2449:
2448:
2444:
2434:
2432:
2428:
2423:
2422:
2418:
2401:
2397:
2387:
2385:
2381:
2370:
2364:
2363:
2359:
2349:
2330:
2329:
2325:
2315:
2313:
2312:on 18 June 2013
2299:
2298:
2294:
2284:
2282:
2273:
2272:
2265:
2259:
2248:
2242:
2241:
2218:
2208:
2206:
2195:"SI base units"
2193:
2192:
2188:
2178:
2176:
2172:
2165:
2160:
2159:
2155:
2148:
2135:
2134:
2127:
2119:
2112:
2106:
2105:
2101:
2091:
2089:
2082:
2067:
2066:
2057:
2047:
2045:
2032:
2031:
2027:
2017:
2015:
2007:
2006:
1999:
1992:
1988:
1978:
1976:
1967:
1966:
1962:
1952:
1950:
1941:
1940:
1936:
1926:
1924:
1915:
1914:
1910:
1903:
1888:
1887:
1883:
1873:
1871:
1862:
1861:
1846:
1836:
1834:
1830:
1823:
1816:
1815:
1798:
1788:
1786:
1777:
1776:
1769:
1759:
1757:
1753:
1746:
1742:
1741:
1724:
1714:
1712:
1703:
1702:
1695:
1684:
1678:
1663:
1656:
1655:
1651:
1640:
1625:
1624:
1609:
1599:
1597:
1588:
1587:
1580:
1570:
1568:
1559:
1558:
1547:
1537:
1535:
1531:
1524:
1519:
1518:
1503:
1495:
1489:
1474:
1467:
1466:
1427:
1418:
1416:
1403:
1402:
1398:
1394:
1389:
1388:
1383:
1379:
1374:
1353:
1344:Smart Metrology
1326:
1311:
1284:
1281:
1268:
1262:
1249:reproducibility
1216:
1194:
1185:
1152:
1143:
1078:
1062:
1019:
983:
958:
934:
917:
909:
834:
833:
820:
796:
779:
747:
740:
729:
727:
718:
711:
687:
681:
672:
662:
652:
648:Planck constant
607:
605:
587:
572:
570:
550:
546:
540:
538:
510:
504:
502:
474:
470:
464:
462:
455:Planck constant
333:
328:
296:
294:Legal metrology
282:
266:Planck constant
254:
245:
172:along with the
147:
141:
35:
28:
23:
22:
15:
12:
11:
5:
3560:
3558:
3550:
3549:
3544:
3534:
3533:
3530:
3529:
3524:
3519:
3514:
3507:
3506:External links
3504:
3502:
3501:
3475:
3449:
3411:
3389:
3367:
3345:
3323:
3301:
3275:
3249:
3223:
3197:
3171:
3134:
3116:
3091:
3059:
3028:
3003:
2994:|journal=
2945:
2936:|journal=
2892:
2866:
2837:
2805:
2794:on 27 May 2012
2779:
2753:
2744:
2728:
2696:
2673:
2647:
2621:
2571:
2537:
2502:
2464:
2442:
2416:
2395:
2357:
2323:
2292:
2263:
2257:
2216:
2186:
2153:
2146:
2125:
2099:
2080:
2055:
2025:
1997:
1986:
1960:
1934:
1908:
1901:
1881:
1844:
1796:
1767:
1722:
1693:
1676:
1649:
1646:on 2013-07-01.
1638:
1607:
1578:
1545:
1501:
1487:
1425:
1395:
1393:
1390:
1387:
1386:
1376:
1375:
1373:
1370:
1369:
1368:
1362:
1356:
1350:Time metrology
1347:
1341:
1335:
1329:
1320:
1314:
1305:
1299:
1293:
1287:
1275:
1264:Main article:
1261:
1258:
1253:climate change
1215:
1212:
1193:
1190:
1184:
1181:
1151:
1148:
1142:
1139:
1134:
1133:
1130:
1127:
1121:
1115:
1109:
1103:
1097:
1077:
1074:
1061:
1058:
1053:
1052:
1049:
1046:
1043:
1018:
1015:
982:
979:
957:
954:
933:
930:
916:
913:
908:
905:
872:
871:
864:
853:
850:
847:
844:
841:
819:
816:
795:
792:
778:
775:
746:
743:
738:
714:speed of light
709:
685:
617:
616:
602:
599:
594:
590:
589:
585:
567:
564:
559:
555:
554:
527:
524:
519:
515:
514:
491:
488:
483:
479:
478:
447:
444:
439:
435:
434:
427:
424:
419:
415:
414:
405:levels of the
399:
396:
391:
387:
386:
383:
380:
377:
332:
329:
327:
324:
312:European Union
295:
292:
281:
278:
270:Kibble balance
253:
250:
244:
241:
140:
137:
128:
127:
124:
121:
111:
110:
107:
104:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
3559:
3548:
3545:
3543:
3540:
3539:
3537:
3528:
3525:
3523:
3520:
3518:
3515:
3513:
3510:
3509:
3505:
3489:
3485:
3479:
3476:
3463:
3459:
3453:
3450:
3445:
3441:
3437:
3433:
3429:
3425:
3418:
3416:
3412:
3399:
3393:
3390:
3377:
3371:
3368:
3355:
3349:
3346:
3333:
3327:
3324:
3311:
3305:
3302:
3289:
3285:
3279:
3276:
3263:
3259:
3253:
3250:
3237:
3233:
3227:
3224:
3211:
3207:
3201:
3198:
3185:
3181:
3175:
3172:
3156:
3149:
3148:
3141:
3139:
3135:
3132:
3128:
3125:
3120:
3117:
3104:
3098:
3096:
3092:
3076:
3069:
3063:
3060:
3047:
3043:
3037:
3035:
3033:
3029:
3016:
3010:
3008:
3004:
2999:
2986:
2967:
2960:
2954:
2952:
2950:
2946:
2941:
2928:
2909:
2902:
2896:
2893:
2880:
2876:
2870:
2867:
2854:
2850:
2844:
2842:
2838:
2822:
2815:
2809:
2806:
2793:
2789:
2783:
2780:
2767:
2763:
2757:
2754:
2748:
2745:
2741:
2737:
2732:
2729:
2719:on 2018-01-21
2715:
2708:
2707:
2700:
2697:
2692:
2685:
2684:
2677:
2674:
2661:
2657:
2651:
2648:
2635:
2631:
2625:
2622:
2606:
2602:
2598:
2594:
2587:
2580:
2578:
2576:
2572:
2556:
2549:
2548:
2541:
2538:
2522:
2515:
2509:
2507:
2503:
2492:on 2011-01-10
2488:
2481:
2480:
2473:
2471:
2469:
2465:
2452:
2446:
2443:
2427:
2420:
2417:
2413:
2409:
2405:
2399:
2396:
2380:
2376:
2369:
2368:
2361:
2358:
2353:
2345:
2341:
2340:
2334:
2327:
2324:
2311:
2307:
2303:
2296:
2293:
2280:
2276:
2270:
2268:
2264:
2260:
2254:
2247:
2246:
2239:
2237:
2235:
2233:
2231:
2229:
2227:
2225:
2223:
2221:
2217:
2204:
2200:
2196:
2190:
2187:
2171:
2164:
2157:
2154:
2149:
2143:
2139:
2132:
2130:
2126:
2118:
2111:
2110:
2103:
2100:
2087:
2083:
2077:
2073:
2072:
2064:
2062:
2060:
2056:
2044:
2040:
2039:Physics World
2036:
2029:
2026:
2014:
2010:
2004:
2002:
1998:
1995:
1990:
1987:
1974:
1970:
1964:
1961:
1948:
1944:
1938:
1935:
1922:
1918:
1912:
1909:
1904:
1898:
1894:
1893:
1885:
1882:
1869:
1865:
1859:
1857:
1855:
1853:
1851:
1849:
1845:
1829:
1822:
1821:
1813:
1811:
1809:
1807:
1805:
1803:
1801:
1797:
1784:
1780:
1774:
1772:
1768:
1752:
1745:
1739:
1737:
1735:
1733:
1731:
1729:
1727:
1723:
1710:
1706:
1700:
1698:
1694:
1690:
1683:
1679:
1673:
1669:
1662:
1661:
1653:
1650:
1645:
1641:
1635:
1631:
1630:
1622:
1620:
1618:
1616:
1614:
1612:
1608:
1595:
1591:
1585:
1583:
1579:
1566:
1562:
1556:
1554:
1552:
1550:
1546:
1530:
1523:
1516:
1514:
1512:
1510:
1508:
1506:
1502:
1494:
1490:
1484:
1480:
1473:
1472:
1464:
1462:
1460:
1458:
1456:
1454:
1452:
1450:
1448:
1446:
1444:
1442:
1440:
1438:
1436:
1434:
1432:
1430:
1426:
1415:on 2011-09-27
1414:
1410:
1408:
1400:
1397:
1391:
1381:
1378:
1371:
1366:
1363:
1360:
1357:
1351:
1348:
1345:
1342:
1339:
1336:
1333:
1330:
1324:
1321:
1318:
1315:
1309:
1306:
1303:
1300:
1297:
1294:
1291:
1288:
1279:
1276:
1273:
1270:
1269:
1267:
1259:
1257:
1254:
1250:
1246:
1245:repeatability
1242:
1241:breathalyzers
1238:
1233:
1231:
1227:
1224:an increased
1222:
1213:
1211:
1209:
1205:
1200:
1199:ISO/IEC 17025
1191:
1189:
1182:
1180:
1178:
1174:
1170:
1166:
1156:
1149:
1147:
1140:
1138:
1131:
1128:
1125:
1122:
1119:
1116:
1113:
1110:
1107:
1104:
1101:
1098:
1095:
1094:
1093:
1091:
1087:
1083:
1075:
1073:
1071:
1067:
1059:
1057:
1050:
1047:
1044:
1041:
1040:
1039:
1036:
1032:
1028:
1024:
1016:
1014:
1012:
1008:
1004:
1000:
996:
987:
980:
978:
975:
971:
967:
963:
955:
953:
951:
947:
943:
939:
931:
929:
926:
922:
914:
912:
906:
904:
902:
898:
894:
890:
885:
881:
877:
869:
865:
851:
848:
845:
842:
839:
832:
831:
830:
828:
824:
817:
815:
813:
808:
800:
793:
791:
788:
784:
776:
774:
772:
768:
764:
760:
751:
744:
742:
737:
725:
721:
715:
708:
704:
700:
696:
692:
684:
679:
675:
669:
665:
659:
655:
649:
645:
641:
637:
633:
627:
625:
615:
603:
600:
598:
595:
592:
591:
584:
580:
568:
565:
563:
560:
557:
556:
536:
532:
528:
525:
523:
520:
517:
516:
500:
496:
492:
489:
487:
484:
481:
480:
460:
456:
452:
448:
445:
443:
440:
437:
436:
432:
428:
425:
423:
420:
417:
416:
412:
408:
404:
400:
397:
395:
392:
389:
388:
384:
381:
378:
376:Base quantity
375:
374:
368:
366:
362:
358:
354:
350:
346:
342:
338:
330:
325:
323:
321:
317:
313:
309:
305:
301:
293:
291:
288:
279:
277:
275:
271:
267:
263:
258:
251:
249:
242:
240:
238:
234:
230:
226:
222:
218:
214:
210:
206:
202:
198:
197:metric system
194:
190:
185:
183:
177:
175:
171:
170:book of rites
167:
162:
160:
156:
152:
146:
138:
136:
133:
125:
122:
120:
116:
115:
114:
108:
105:
102:
101:
100:
97:
95:
91:
87:
83:
82:
77:
76:metric system
73:
69:
65:
58:
54:
50:
46:
41:
37:
33:
19:
3492:. Retrieved
3478:
3466:. Retrieved
3452:
3427:
3423:
3402:. Retrieved
3398:"About UKAS"
3392:
3380:. Retrieved
3370:
3358:. Retrieved
3348:
3336:. Retrieved
3326:
3314:. Retrieved
3304:
3292:. Retrieved
3287:
3278:
3266:. Retrieved
3262:the original
3252:
3240:. Retrieved
3236:www.bipm.org
3235:
3226:
3214:. Retrieved
3210:the original
3200:
3188:. Retrieved
3174:
3162:. Retrieved
3146:
3119:
3107:. Retrieved
3082:. Retrieved
3075:the original
3062:
3050:. Retrieved
3042:"ABOUT ILAC"
3019:. Retrieved
2985:cite journal
2973:. Retrieved
2927:cite journal
2915:. Retrieved
2895:
2883:. Retrieved
2879:the original
2869:
2857:. Retrieved
2853:the original
2828:. Retrieved
2821:the original
2808:
2798:26 September
2796:. Retrieved
2792:the original
2782:
2772:26 September
2770:. Retrieved
2756:
2747:
2731:
2721:, retrieved
2714:the original
2705:
2699:
2682:
2676:
2666:26 September
2664:. Retrieved
2660:the original
2650:
2638:. Retrieved
2624:
2612:. Retrieved
2592:
2562:. Retrieved
2546:
2540:
2528:. Retrieved
2494:. Retrieved
2487:the original
2478:
2455:. Retrieved
2445:
2433:. Retrieved
2419:
2403:
2398:
2386:. Retrieved
2366:
2360:
2337:
2326:
2314:. Retrieved
2310:the original
2305:
2295:
2283:. Retrieved
2279:the original
2244:
2207:. Retrieved
2198:
2189:
2177:. Retrieved
2156:
2137:
2117:the original
2108:
2102:
2090:. Retrieved
2070:
2046:. Retrieved
2038:
2028:
2016:. Retrieved
2013:ScienceDaily
2012:
1989:
1977:. Retrieved
1963:
1951:. Retrieved
1937:
1925:. Retrieved
1911:
1891:
1884:
1872:. Retrieved
1835:. Retrieved
1819:
1787:. Retrieved
1758:. Retrieved
1713:. Retrieved
1688:
1659:
1652:
1644:the original
1628:
1598:. Retrieved
1569:. Retrieved
1565:the original
1536:. Retrieved
1470:
1417:. Retrieved
1413:the original
1406:
1399:
1380:
1234:
1217:
1195:
1186:
1161:
1144:
1135:
1089:
1085:
1079:
1063:
1054:
1020:
992:
959:
935:
918:
910:
900:
896:
892:
888:
883:
879:
875:
873:
867:
821:
809:
805:
787:gauge blocks
780:
756:
735:
717:
706:
682:
671:
661:
651:
628:
620:
582:
534:
498:
458:
407:ground state
334:
297:
283:
259:
255:
246:
239:, or CGPM).
186:
178:
163:
159:the pyramids
148:
129:
112:
98:
79:
63:
62:
36:
18:Metrological
3547:Measurement
3486:. EURAMET.
3460:. EURAMET.
3430:: 155–163.
3424:Measurement
2285:16 February
2209:15 February
2179:28 February
2092:17 February
1953:23 February
1927:28 February
1874:28 February
1781:. EURAMET.
1600:28 February
1571:28 February
1538:16 February
1332:Metrication
818:Uncertainty
812:calibration
759:realisation
722:), and the
676:), and the
503:1.602176634
411:caesium-133
385:Definition
217:photometric
182:Magna Carta
132:calibration
68:measurement
32:Meteorology
3536:Categories
3360:25 January
2723:2018-11-22
2496:2014-06-13
2354:required.)
2168:. WELMEC.
1419:2018-02-21
1392:References
1338:Metrologia
1237:radar guns
1088:(GUM) and
732:10 Hz
610:10 Hz
571:6.02214076
463:6.62607015
451:as of 2019
314:and among
219:units and
166:Artificers
143:See also:
3542:Metrology
2640:1 October
2601:1368-6550
2333:"Realise"
989:BIPM seal
849:±
827:measurand
777:Standards
614:steradian
449:Defined (
403:hyperfine
243:Subfields
64:Metrology
3488:Archived
3462:Archived
3404:25 March
3382:25 March
3316:25 March
3294:25 March
3242:24 March
3190:24 March
3184:Archived
3164:24 March
3155:Archived
3127:Archived
3109:25 March
3084:24 March
3052:24 March
3046:Archived
3021:25 March
2975:24 March
2966:Archived
2917:24 March
2908:Archived
2885:26 March
2859:26 March
2830:26 March
2766:Archived
2634:Archived
2605:Archived
2555:Archived
2521:Archived
2457:23 March
2435:23 March
2414:page 616
2379:Archived
2203:Archived
2170:Archived
2086:Archived
2048:23 March
2018:23 March
1973:Archived
1971:. BIPM.
1947:Archived
1945:. BIPM.
1921:Archived
1868:Archived
1828:Archived
1783:Archived
1751:Archived
1709:Archived
1682:Archived
1594:Archived
1529:Archived
1493:Archived
1260:See also
899:= 1 and
783:standard
769:for the
632:kilogram
551:kg m s K
539:1.380649
537:, to be
501:, to be
461:, to be
442:kilogram
326:Concepts
272:and the
3494:9 March
3468:9 March
3432:Bibcode
3338:18 June
3268:5 March
3216:5 March
2614:2 March
2564:2 March
2530:2 March
2388:1 March
2316:1 March
1837:9 March
1789:9 March
1760:5 March
1715:5 March
1214:Impacts
1179:(NPL).
1126:(IUPAP)
1120:(IUPAC)
712:), the
699:candela
666:), the
656:), the
597:candela
409:of the
155:granite
139:History
57:voltage
3400:. UKAS
3378:. NATA
3105:. ILAC
3017:. OIML
2599:
2431:. NIST
2410:
2255:
2144:
2078:
1979:26 Sep
1899:
1674:
1636:
1485:
1108:(IFCC)
1027:French
999:French
974:Sèvres
966:French
942:French
874:Where
697:, and
691:second
642:, and
640:kelvin
636:ampere
522:kelvin
486:ampere
475:kg m s
431:vacuum
418:Length
394:second
382:Symbol
363:, and
341:length
308:WELMEC
287:device
233:French
205:French
49:weight
45:NIST-4
3334:. PTB
3332:"PTB"
3158:(PDF)
3151:(PDF)
3078:(PDF)
3071:(PDF)
2969:(PDF)
2962:(PDF)
2911:(PDF)
2904:(PDF)
2824:(PDF)
2817:(PDF)
2717:(PDF)
2710:(PDF)
2687:(PDF)
2608:(PDF)
2589:(PDF)
2558:(PDF)
2551:(PDF)
2524:(PDF)
2517:(PDF)
2490:(PDF)
2483:(PDF)
2429:(PDF)
2382:(PDF)
2371:(PDF)
2348:
2249:(PDF)
2173:(PDF)
2166:(PDF)
2120:(PDF)
2113:(PDF)
1831:(PDF)
1824:(PDF)
1754:(PDF)
1747:(PDF)
1685:(PDF)
1664:(PDF)
1532:(PDF)
1525:(PDF)
1496:(PDF)
1475:(PDF)
1372:Notes
1114:(ISO)
1102:(IEC)
695:metre
553:..."
513:..."
477:..."
422:metre
413:atom
193:metre
3496:2017
3470:2017
3406:2018
3384:2018
3362:2022
3340:2023
3318:2018
3296:2018
3288:NIST
3270:2017
3244:2018
3218:2017
3192:2017
3166:2017
3111:2018
3086:2017
3054:2017
3023:2018
2998:help
2977:2017
2940:help
2919:2017
2887:2018
2861:2018
2832:2018
2800:2012
2774:2012
2668:2012
2642:2012
2616:2017
2597:ISSN
2566:2017
2532:2017
2459:2018
2437:2018
2408:ISBN
2390:2017
2318:2012
2287:2017
2253:ISBN
2211:2017
2181:2017
2142:ISBN
2094:2017
2076:ISBN
2050:2018
2020:2018
1981:2013
1955:2017
1929:2017
1897:ISBN
1876:2017
1839:2017
1791:2017
1762:2017
1717:2017
1672:ISBN
1634:ISBN
1602:2017
1573:2017
1540:2017
1483:ISBN
1479:ISTE
1247:and
1239:and
1080:The
1064:The
1021:The
993:The
960:The
936:The
919:The
757:The
644:mole
562:mole
438:Mass
390:Time
379:Name
349:time
345:mass
335:The
304:OIML
55:and
51:via
43:The
3440:doi
1230:GDP
870:= 2
771:ohm
728:540
726:of
606:540
566:mol
547:J K
511:A s
471:J s
3538::
3438:.
3428:69
3426:.
3414:^
3286:.
3234:.
3137:^
3094:^
3031:^
3006:^
2989::
2987:}}
2983:{{
2948:^
2931::
2929:}}
2925:{{
2840:^
2689:.
2603:.
2591:.
2574:^
2505:^
2467:^
2336:.
2304:.
2266:^
2219:^
2197:.
2128:^
2084:.
2058:^
2041:.
2037:.
2011:.
2000:^
1847:^
1799:^
1770:^
1725:^
1696:^
1680:.
1666:.
1610:^
1581:^
1548:^
1504:^
1491:.
1481:.
1477:.
1428:^
1029::
1001::
968::
944::
781:A
739:cd
710:Cs
705:(Δ
693:,
638:,
634:,
626:.
601:cd
581:,
575:10
543:10
533:,
507:10
497:,
467:10
457:,
446:kg
359:,
355:,
351:,
347:,
343:,
235::
207::
3498:.
3472:.
3446:.
3442::
3434::
3408:.
3386:.
3364:.
3342:.
3320:.
3298:.
3272:.
3246:.
3220:.
3194:.
3168:.
3113:.
3088:.
3056:.
3025:.
3000:)
2996:(
2979:.
2942:)
2938:(
2921:.
2889:.
2863:.
2834:.
2802:.
2776:.
2742:.
2670:.
2644:.
2618:.
2568:.
2534:.
2499:.
2461:.
2439:.
2392:.
2346:.
2320:.
2289:.
2213:.
2183:.
2150:.
2096:.
2052:.
2022:.
1983:.
1957:.
1931:.
1905:.
1878:.
1841:.
1793:.
1764:.
1719:.
1604:.
1575:.
1542:.
1422:.
1405:"
1025:(
997:(
964:(
940:(
901:k
897:k
893:k
889:k
884:k
880:U
876:y
868:k
852:U
846:y
843:=
840:Y
736:K
730:Ă—
719:c
716:(
707:ν
686:A
683:N
680:(
673:k
670:(
663:e
660:(
653:h
650:(
608:Ă—
586:A
583:N
573:Ă—
541:Ă—
535:k
526:K
505:Ă—
499:e
490:A
465:Ă—
459:h
426:m
398:s
231:(
203:(
34:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
