The invention relates to a method and to a switching device (4) and a measurement system (1). In the method according to the invention for determining time differences between measurement signals measured by at least two couple measurement devices (2, 3), a time basis signal is first generated for the measurement devices (2, 3). A common reference signal is further generated by a signal generator (5). The common reference signal is fed to measurement signal inputs (8, 9) of the coupled measuring devices (2, 3) via the switching device (4). A measurement signal is then fed to said measurement signal inputs (8, 9) of the coupled measuring devices (2, 3) and the time position of the measurement signals relative to the reference signal is determined in each of the coupled measuring devices (2, 3). The switching device (4), to this end, has a first measuring device connection (12) and a second measuring device connection (13) connected to the measurement signal inputs (8, 9) of the first measuring device (2) and the second measuring device (3). A reference signal is alternately fed via the measuring device connections (12, 13) of the switching device (4) to the first or the second measuring device (2, 3) by connecting the first measuring device connection (12) to the reference signal input (22) or a first measuring connection (14), or by connecting the second measuring device connection (13) to the reference signal input (22) or the second measuring connection (15).