Realization

From WikiChem
Revision as of 14:40, 29 July 2010 by Physchim62 (talk | contribs)
Jump to: navigation, search

In metrology, the realization (or embodiment) of a measurement unit or a measurement scale is the practical method by which the unit can be measured (or the scale put into practice). The realization of a unit or of a scale creates one or more measurement standards against which an unknown physical quantity of the same kind can be compared.[1]

There are three general methods of realizing a unit or a scale. The first and most obvious is simply to follow the definition of the unit or scale, for example by measuring the distance travelled by light in vacuum in 1299,792,458 of a second to realize the metre. The second method is to use a physical phenomenon which is accepted to be equivalent to the definition, for example realizing the metre by laser interferometry with a measured frequency of light. The third method is to have a physical standard, for example the now-obsolete International Prototype Metre.[1]

References

Error creating thumbnail: Unable to save thumbnail to destination
This page is currently licensed under the Creative Commons Attribution 3.0 Unported license and any later versions of that license.