Historical and sociological studies have shown that precision measurem
ent and metrology play an important social and scientific role. This p
aper contrasts the dynamics of four metrological configurations. The f
irst concerns an instrument for routine car repair. It displays the ne
twork of institutions, conventions and procedures allowing for the con
servation of legal metrological precision. Such resources are not yet
available during the genesis of an instrument. Very often in scientifi
c laboratories, instruments and their metrology are elaborated simulta
neously. The three other case studies analyze this construction by loo
king at ordinary metrological operations: the collective elaboration o
f standards; the translation of scientific instruments in metrological
laboratories; and the intercomparison of instruments. It appears that
the diversity and heterogeneity of resources associated with metrolog
ical networks result in different ways of articulating the natural and
conventional character of precision measurement.