Standard deviation in RV values for SACY sources, excluding known SB2 systems, as a function of V magnitude. UVES and FEROS values – blue dots and UVES, FEROS and archival data – red circles.The variables, 1σ_s and 3σ_s, represent one standard deviation and three standard deviations respectively, for both UVES and FEROS data. The shaded area contains SB1 candidate multiple systems. The variable 3σ_a, represents three standard deviations including archival data.