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Scientific metrology

Metrology at the highest level which deals with the organisation and development of measurement standards and with their maintenance (reference: Metrology in Short)*

Legal metrology

The part of metrology relating to activities which result from statutory requirements and concern measurements, units of measurement, measuring instruments and methods of measurement, and which are performed by competent bodies (reference: VIML)*


Set of operations having the object of determining a value of a quantity (reference: VIM)*

Measuring instrument

Device intended to be used to make measurements, alone or in conjunction with supplementary devices (reference: VIM)*

(Measurement) standard, etalon

Material measure, measuring instrument, reference material or measuring system intended to define, realise, conserve or reproduce a unit or one or more values of a quantity to serve as a reference (reference: VIM) *

National (measurement) standard

Standard recognised by a national decision to serve, in a country, as the basis for assigning values to other standards of the quantity concerned (reference: VIM)*

Reference standard

Standard, generally having the highest metrological quality available at a given location or in a given organisation, from which measurements made there are derived (reference: VIM)*


Set of operations that establish, under specified conditions, the relationship between values of quantities indicated by a measuring instrument or measuring system, or values represented by a material measure or a reference material, and the corresponding values realised by standards (reference: VIM)*


Procedure (other than type approval) which includes the examination and marking and/or issuing of a verification certificate, that ascertains and confirms that the measuring instrument complies with the statutory requirements (reference: VIML)*

Result of a measurement

Value attributed to a measurand, obtained by measurement (reference: VIM).*

A complete statement of the result of a measurement includes information about the uncertainty of measurement.


Property of the result of a measurement or the value of a standard whereby it can be related to stated references, usually national or international standards, through an unbroken chain of comparisons all having stated uncertainties (reference: VIM)*

Uncertainty of measurement

Parameter, associated with the result of a measurement, that characterises the dispersion of the values that could reasonably be attributed to the measurand (reference: VIM)*