A method for operating a measuring device, in particular, a vectorial network analyzer, which can be connected via at least two ports to a device under test, with excitation units assigned to each port, wherein each excitation unit provides a signal generator, with which the assigned port can be supplied with an excitation signal, provides the following procedural stages: a measurement at measuring positions of the actual phase offset between the excitation signals output at the ports; and a variation of the frequency of at least one of the two signal generators during a correction interval so that a specified set phase offset is achieved at reference positions between the excitation signals output at the ports.