Editing Measurement (section)

=== Standards ===
{{see also|Metrology#Standards}}

With the exception of a few fundamental [[quantum]] constants, units of measurement are derived from historical agreements. Nothing inherent in nature dictates that an [[inch]] has to be a certain length, nor that a [[mile]] is a better measure of distance than a [[kilometre]]. Over the course of human history, however, first for convenience and then out of necessity, standards of measurement evolved so that communities would have certain common benchmarks. Laws regulating measurement were originally developed to prevent fraud in commerce.

[[Units of measurement]] are generally defined on a scientific basis, overseen by governmental or independent agencies, and established in international treaties, pre-eminent of which is the [[General Conference on Weights and Measures]] (CGPM), established in 1875 by the [[Metre Convention]], overseeing the International System of Units (SI).  For example, the metre was redefined in 1983 by the CGPM in terms of the speed of light, the kilogram was redefined in 2019 in terms of the [[Planck constant]] and the international yard was defined in 1960 by the governments of the United States, United Kingdom, Australia and South Africa as being ''exactly'' 0.9144 metres.

In the United States, the National Institute of Standards and Technology ([[NIST]]), a division of the [[United States Department of Commerce]], regulates commercial measurements. In the United Kingdom, the role is performed by the [[National Physical Laboratory (United Kingdom)|National Physical Laboratory]] (NPL), in Australia by the [[National Measurement Institute, Australia|National Measurement Institute]],<ref>{{cite web|url=http://www.measurement.gov.au/Pages/about.aspx |title=About Us |website=National Measurement Institute of Australia|date=3 December 2020 }}</ref> in South Africa by the [[Council for Scientific and Industrial Research]] and in India the [[National Physical Laboratory of India]].