Magnetic-inductive flowmeter comprising a measuring tube, a first electrode, a second electrode, a magnetic field generator, an impedance signal generator, a coupling device and a control device, wherein the first electrode and the second electrode are arranged on the measuring tube for direct contact with a medium in the measuring tube, wherein the magnetic field generator is designed to generate an alternating magnetic field with a positive magnetic field phase and a negative magnetic field phase in the medium in the measuring tube, wherein the impedance signal generator is designed to generate excitation signals (i), wherein the coupling device comprises a first capacitor, a second capacitor, a first signal path and a second signal path, wherein the first signal path interconnects the impedance signal generator and the first electrode and the second signal path interconnects the impedance signal generator and the second electrode for transmitting the excitation signals (i), wherein the control device is designed for determining a flow rate of a medium through the measuring tube using flow rate measurement signals caused by the alternating magnetic field in the medium and measurable at the first electrode and the second electrode, and wherein the control device is designed to determine an impedance of the medium in the measuring tube using impedance measurement signals induced by the excitation signals (i) and measurable at the first electrode and the second electrode, characterized in that the coupling device has a third capacitor, a fourth capacitor, a first switch and a second switch that the first switch, the first capacitor and the third capacitor are connected to one another in such a way and the first switch is designed in such a way that, in a first switching state (S 1), only the first capacitor and, in a second switching state (S 2), only the third capacitor are connected in the first signal path that the second switch, the second capacitor and the fourth capacitor are connected to one another in such a way and the second switch is designed in such a way that, in a first switching state (S 1), only the second capacitor and, in a second switching state (S 2), only the fourth capacitor is connected into the second signal path, and that the control device is designed to set the first switch and the second switch to the first switching state (S 1) for a duration of the positive magnetic field phase and to set them to the second switching state (S 2) for a duration of the negative magnetic field phase. wherein the first electrode and the second electrode are arranged on the measuring tube for direct contact with a medium in the measuring tube, wherein the magnetic field generator is designed to generate an alternating magnetic field with a positive magnetic field phase and a negative magnetic field phase in the medium in the measuring tube, wherein the impedance signal generator is designed to generate excitation signals (i), wherein the coupling device comprises a first capacitor, a second capacitor, a first signal path and a second signal path, wherein the first signal path interconnects the impedance signal generator and the first electrode and the second signal path interconnects the impedance signal generator and the second electrode for transmitting the excitation signals (i), wherein the control device is designed for determining a flow rate of a medium through the measuring tube using flow rate measurement signals caused by the alternating magnetic field in the medium and measurable at the first electrode and the second electrode, and wherein the control device is designed to determine an impedance of the medium in the measuring tube using impedance measurement signals induced by the excitation signals (i) and measurable at the first electrode and the second electrode, characterized in that the coupling device has a third capacitor, a fourth capacitor, a first switch and a second switch that the first switch, the first capacitor and the third capacitor are connected to one another in such a way and the first switch is designed in such a way that, in a first switching state (S 1), only the first capacitor and, in a second switching state (S 2), only the third capacitor are connected in the first signal path that the second switch, the second capacitor and the fourth capacitor are connected to one another in such a way and the second switch is designed in such a way that, in a first switching state (S 1), only the second capacitor and, in a second switching state (S 2), only the fourth capacitor is connected into the second signal path, and that the control device is designed to set the first switch and the second switch to the first switching state (S 1) for a duration of the positive magnetic field phase and to set them to the second switching state (S 2) for a duration of the negative magnetic field phase.