According to the invention, a time synchronization of phase between measurement devices that do not share a same clock for their respective sampling of the signals is carried out by a time tagging of samples of the signals in time blocks followed by an adjustment of the phase values of components of interest of the signals in the regrouped time blocks so that the values refer to common time references between the measurement devices. The tagging is carried out with a synchronization signal available to the measurement devices, completed with count values provided by a counter operated by a reference clock for each measurement device.