NOTE 1 Measurement does not apply to nominal properties.
NOTE 2 Measurement implies comparison of quantities or counting of entities.
NOTE 3 Measurement presupposes a description of the quantity commensurate with the intended use of a measurement result, a measurement procedure, and a calibrated measuring system operating according to the specified measurement procedure, including the measurement conditions.
ANNOTATION (informative) [3 December 2013] "experimentally obtaining" in the definition is to be interpreted in a broad sense of including not only direct physical comparison, but also of using models and calculations that are based on theoretical considerations.
ANNOTATION (informative) [5 June 2014] Here "quantity value" can be replaced with "value" without ambiguity: "process of experimentally obtaining one or more values that can reasonably be attributed to a quantity".
ANNOTATION (for Note 3) (informative) [3 December 2013] This Note is intended to explain what is needed in order to carry out a measurement. It is first necessary to choose a target measurement uncertainty, and then choose an appropriate procedure and measuring system for performing the measurement in order not to exceed the target uncertainty.