Abstract: A physical parameter represented by variation in time of a physical magnitude G capable of varying between a minimum value G.sub.min and a maximum value G.sub.max is determined. The physical magnitude G is measured at variable time intervals referred to as sampling times. After each measurement of the physical magnitude G, the corresponding value of the physical parameter, and also the theoretical maximum error that could have occurred in the determination of the physical parameter are determined. The sampling time prior to each new measurement of the physical magnitude G is determined in such a manner as to ensure that a predetermined error threshold E.sub.max is not exceeded while determining the value of the physical parameter corresponding to the new measurement of the physical magnitude G.