ABSTRACT
Abstract Every measurement i s f a t a l l y prone to errors, the nature and causes of which are very numerous : the "true value" of the measured quantity i s never accessible, and moreover, i t is not possible to compute the t o t a l error on the result of measurement. Nevertheless one can estimate the different errors and combine them in order to obtain the uncertainty of the measurement and i t s components. The expressed result must always mention the uncertainty with which i t i s known. Some work i s nowadays in progress at ISO, and i t would lead to standards or guides, aiming at helping testing or metrological laboratories in that delicate question, especially in the framework of recommendations issued by the "Bureau International des Poids et Mesures". Keywords: Communication, Measurement, Error, Uncertainty, Standardisation, Metrology.
