Metrology is variously described as the science of measurement; the science of accuracy and precision; the history of measures; the history of measurement and other definitions. It is a field of study which has been highly politicized and nationalized with sharp even severe rhetoric as the field progressed.

Introduction

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Metrology, as defined by the International Organization of Legal Metrology (OIML) in its 2000 publication International Vocabulary of Terms in Legal Metrology is the "Science of Measurement." Legal metrology is further defined in this same international standard as: "part of metrology relating to 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." International Bureau of Weights and Measures (BIPM) further defines metrology as "...the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of Science and Technology." [http://www.bipm.org/en/bipm/metrology/" target="_blank" >^*

Historical development

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Metrology was originally a study of historical measurement examining ancient, beginning of history documents from Assyria, Egypt, Greece and Roman origin. Early metrologists asserted that early cultures used a system of measurement in commerce that created a foundation for the study of scientific measurement. The studies by John Greaves (1602-1652) and Eduard Bernard (1638-1697) assert that a basic unit of measurement was used between cultures of the time based on the foot or cubit and that the basic measure of length cubed and filled with rainwater gives the basic measure of weight as a standard.

There seems to have been a great deal of politicization of the study of metrology, especially at the beginning of the 20th century which became nationalistic in nature. The battle lines were drawn between English, French, Italian and German interests and schools of thought. Many schools of thought proclaimed themselves as 'new' and 'improved' versions of metrology and clashed severely with the other schools.

La metrologia non é scienza, é un incubo. (Metrology is not a science; it’s a nightmare). -G. De Sanctis

Historically, measures of space are defined as discrete units of length, area, and volume. Measures of time are defined as a length of time for which a phenomena may be observed. Time is thought of both as an ongoing and continuing process and as having a period or duration for an event and so may be additionally described as cyclical, sequential, periodic or a singularity. Measures of other physical properties such as weight are defined first as physical properties of the space time continuum and then given additional descriptors such as mass and energy.

Mechanisms of metrology

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One small subset of this study has to do with standards of measure. A small subset of that area of study is the definition of standards and the scientific methodology of ensuring that standards of measure meet specified degrees of accuracy and precision. In the United States, the master reference standards are maintained through the National Institute of Standards and Technology (NIST). By convention, a standard is ten times more accurate and precise than the measurement being tested.

The process of comparison against a standard, and making any necessary adjustments, is commonly called calibration. Detailed records are maintained for each item that is calibrated to ensure "traceability", and that the item met clearly identified specifications for both accuracy and precision in all its operating parameters.

Collaboration between NIST and its counterparts in other countries and with the BIPM ensures the highest achievable standards.

References

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• Organisation Internationale de Metrologie Legale. (2000), International Vocabulary of Terms in Legal Metrology, ^* http://www.oiml.org/publications/V/V001-ef00.pdf.
• Bureau International des Poids et Mesures. (2005), "What is metrology", Copyright BIPM 2004, ^* http://www.bipm.org/en/bipm/metrology/.
• Sarle, W. (1995), Measurement theory: Frequently asked questions, Copyright 1995 by Warren S. Sarle, Cary, NC, USA ^* SAS Institute web pages: ftp://ftp.sas.com/pub/neural/measurement.faq
• Bureau International des Poids et Mesures. (2000), The International System of Units (SI), ^* BIPM web pages: http://www.bipm.fr/enus/3_SI/
• Bureau International des Poids et Mesures. (2000), The Convention of the meter, ^* BIPM web pages: http://www.bipm.fr/enus/1_Convention/
• Melville, D.J. (2001). Sumerian metrological numeration systems, Mesopotamian Mathematics, ^* St. Lawrence University web pages, http://it.stlawu.edu/%7Edmelvill/mesomath/sumerian.html
• National Institute of Standards and Technology. (1999), The NIST Reference of Constants, Units, and Uncertainty, ^* NIST web pages: http://physics.nist.gov/cuu/index.html
• National Institute of Standards and Technology / Sematech. (n.d.). Engineering Statistics Handbook. ^* NIST web pages: http://www.nist.gov/itl/div898/handbook/
• National Physical Laboratory, UK - National Measurement Laboratory - Metrology related resources including many free PDF downloads including Good Practice Guides: ^* http://www.npl.co.uk/

External links

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• National Institute of Standards and Technology (NIST)
• Bureau International des Poids et Mesures (BIPM)
• National Physical Laboratory
• U.S. Naval Observatory
• National Conference of Standards Laboratories (NCSL)
• Nederlands Meetinstituut (NMi)
• Adhoc-Vision French company specialized in metrology

Metrology | Metrologie | Metrologie | Métrologie | Metrologie | Metrologia | Метрология