property of a phenomenon, body, or substance, where the property has a magnitude that can be expressed as a number and a reference

quantity intended to be measured

process of experimentally obtaining one or more quantity values that can reasonably be attributed to a quantity

quantity value provided by a measuring instrument or a measuring system

phenomenon serving as a basis of a measurement

generic description of a logical organization of operations used in a measurement

detailed description of a measurement according to one or more measurement principles and to a given measurement method, based on a measurement model and including any calculation to obtain a measurement result

quantity that, in a direct measurement, does not affect the quantity that is actually measured, but affects the relation between the indication and the measurement result

set of quantity values being attributed to a measurand together with any other available relevant information

device used for making measurements, alone or in conjunction with one or more supplementary devices

set of one or more measuring instruments and often other devices, including any reagent and supply, assembled and adapted to give information used to generate measured quantity values within specified intervals for quantities of specified kinds

property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty

operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication

provision of objective evidence that a given item fulfills specified requirements

verification, where the specified requirements are adequate for an intended use

closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under the specified conditions

closeness of agreement between a measured quantity value and a true quantity value of a measurand

value consistent with the definition of a quantity

value attributed by agreement to a quantity for a given purpose

non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand

measured quantity value minus a reference quantity value

component of measurement error that in replicate measurements varies in an unpredictable manner

component of measurement error that in replicate measurements remains constant or varies in a predictable manner

compensation for an estimated systematic effect