Metrology

Not to be confused with Meteorology.

The NIST-4 Kibble balance, which is used to measure weight via electric current and voltage. With this instrument, the measurement of mass is no longer dependent on a defined mass standard and is instead dependent on natural physical constants.

Metrology is the scientific study of measurement.[1] It establishes a common understanding of units, crucial in linking human activities.[2] 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 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.[3][4] 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.[5]

Metrology is divided into three basic overlapping activities:[6][7]

  • The definition of units of measurement
  • The realisation of these units of measurement in practice
  • Traceability—linking measurements made in practice to the reference standards

These overlapping activities are used in varying degrees by the three basic sub-fields of metrology:[6]

  • Scientific or fundamental metrology, concerned with the establishment of units of measurement
  • Applied, technical or industrial metrology—the application of measurement to manufacturing and other processes in society
  • Legal metrology, covering the regulation and statutory requirements for measuring instruments and methods of measurement

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.[8][9] 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).[10][11] 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.[11]

  1. ^ "What is metrology? Celebration of the signing of the Metre Convention, World Metrology Day 2004". BIPM. 2004. Archived from the original on 2011-09-27. Retrieved 2018-02-21.
  2. ^ Cite error: The named reference FCM was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference BGtoM was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference French-History was invoked but never defined (see the help page).
  5. ^ "Resolution 12 of the 11th CGPM (1960)". Bureau International des Poids et Mesures. Archived from the original on 14 May 2013. Retrieved 28 February 2017.
  6. ^ a b Czichos, Horst; Smith, Leslie, eds. (2011). Springer Handbook of Metrology and Testing (2nd ed.). Springer. 1.2.2 Categories of Metrology. ISBN 978-3-642-16640-2. Archived from the original on 2013-07-01.
  7. ^ Collège français de métrologie [French College of Metrology] (2006). Placko, Dominique (ed.). Metrology in Industry – The Key for Quality (PDF). International Society for Technology in Education (ISTE). 2.4.1 Scope of legal metrology. ISBN 978-1-905209-51-4. Archived (PDF) from the original on 2012-10-23. ... 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.
  8. ^ "National Measurement System". National Physical Laboratory. Archived from the original on 15 February 2017. Retrieved 5 March 2017.
  9. ^ Cite error: The named reference NQI was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference MSC was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference AusEconomy was invoked but never defined (see the help page).