Abstract
This paper presents a relational modeling of measurement which is complementary to the standard representational point of view: by focusing on the empirical character of the mcasurand-rclatcd comparison between objects, this modeling emphasizes the role of the measuring systems as the devices which operatively perform such a comparison. The non-idealities of the operation are accounted in terms of non-transitivity of the substicurability relation between measured objects, due to an uncertainty on the mcasurand value remaining after the measurement The mctrological structure of traccability is shown to be an effective solution to cope with the problem of the general non-transitivity of measurement results.