A contact-monitoring device for monitoring an electrical, three-pole changeover contact, comprising: - a signal generator that is configured to generate a preferably high-frequency monitoring signal (S Ü); - a preferably inductive coupling device, which is arranged downstream of the signal generator; - a sensing circuit, which is arranged downstream of the coupling device and is coupled or couplable to the changeover contact; wherein by means of the sensing circuit, which is coupled to the signal generator via the coupling device, the monitoring-signal generation of the signal generator and thus the monitoring signal (S Ü) and/or a signal derived from the monitoring signal (S Ü) is changeable depending on a switching position of the changeover contact; - an evaluation device, which is configured to detect the monitoring signal (S Ü) and/or the signal derived from the monitoring signal (S Ü) and/or a change in the monitoring signal (S Ü) and/or a change in the signal derived from the monitoring signal (S Ü) in order thereby to monitor the changeover contact, characterized in that the sensing circuit is configured to change the monitoring signal (S Ü) and/or the signal derived from the monitoring signal (S Ü) differently for at least three, preferably four, different switching positions of the changeover contact, and the sensing circuit comprises one or more impedances (131 - 138) and is configured to provide, together with the changeover contact, a total impedance at the coupling device that varies with the switching position of the changeover contact. - a signal generator that is configured to generate a preferably high-frequency monitoring signal (S Ü); - a preferably inductive coupling device, which is arranged downstream of the signal generator; - a sensing circuit, which is arranged downstream of the coupling device and is coupled or couplable to the changeover contact; wherein by means of the sensing circuit, which is coupled to the signal generator via the coupling device, the monitoring-signal generation of the signal generator and thus the monitoring signal (S Ü) and/or a signal derived from the monitoring signal (S Ü) is changeable depending on a switching position of the changeover contact; - an evaluation device, which is configured to detect the monitoring signal (S Ü) and/or the signal derived from the monitoring signal (S Ü) and/or a change in the monitoring signal (S Ü) and/or a change in the signal derived from the monitoring signal (S Ü) in order thereby to monitor the changeover contact, - an evaluation device, which is configured to detect the monitoring signal (S Ü) and/or the signal derived from the monitoring signal (S Ü) and/or a change in the monitoring signal (S Ü) and/or a change in the signal derived from the monitoring signal (S Ü) in order thereby to monitor the changeover contact, characterized in that the sensing circuit is configured to change the monitoring signal (S Ü) and/or the signal derived from the monitoring signal (S Ü) differently for at least three, preferably four, different switching positions of the changeover contact, and the sensing circuit comprises one or more impedances (131 - 138) and is configured to provide, together with the changeover contact, a total impedance at the coupling device that varies with the switching position of the changeover contact.