Electrosurgical system for treating a tissue, comprising: - a first electrode and a second electrode, each configured to be conductively connected to the tissue to be treated; - a high-frequency high-voltage supply unit that can be electrically connected to the first electrode via a first electrical line and to the second electrode via a second electrical line, and that is configured to supply a specified AC treatment voltage to these electrodes; - A measuring unit that can be electrically connected to the first electrode and second electrode and that has a measurement voltage supply module that is configured to supply an AC measurement voltage of at least a first frequency and a second frequency, wherein the measuring unit is further configured to receive, via the first electrode and second electrode, an electrical response signal for the first frequency and second frequency and to use it to determine at least one property of a tissue located between the first electrode and second electrode; - a control unit that is configured, during operation of the electrosurgical system, at the start of a measurement, to interrupt the electrical connection of the high-frequency high-voltage supply unit to the first or second electrode and ensure the electrical connection of the measuring unit to the first electrode and second electrode; and, at the end of a measurement, to interrupt the electrical connection of the measuring unit to the first or second electrode and ensure the electrical connection of the high-frequency high-voltage supply unit to the first electrode and second electrode, wherein the control unit is electrically connected to the measuring unit, characterized in that the control unit is further configured to trigger, after the start of a measurement, an activation of the AC measurement voltage at the first frequency via the measurement voltage supply module and to trigger, before the end of the measurement, a deactivation of the AC measurement voltage of the measurement voltage supply module. - a first electrode and a second electrode, each configured to be conductively connected to the tissue to be treated; - a high-frequency high-voltage supply unit that can be electrically connected to the first electrode via a first electrical line and to the second electrode via a second electrical line, and that is configured to supply a specified AC treatment voltage to these electrodes; - A measuring unit that can be electrically connected to the first electrode and second electrode and that has a measurement voltage supply module that is configured to supply an AC measurement voltage of at least a first frequency and a second frequency, wherein the measuring unit is further configured to receive, via the first electrode and second electrode, an electrical response signal for the first frequency and second frequency and to use it to determine at least one property of a tissue located between the first electrode and second electrode; - a control unit that is configured, during operation of the electrosurgical system, at the start of a measurement, to interrupt the electrical connection of the high-frequency high-voltage supply unit to the first or second electrode and ensure the electrical connection of the measuring unit to the first electrode and second electrode; and, at the end of a measurement, to interrupt the electrical connection of the measuring unit to the first or second electrode and ensure the electrical connection of the high-frequency high-voltage supply unit to the first electrode and second electrode, wherein the control unit is electrically connected to the measuring unit, characterized in that the control unit is further configured to trigger, after the start of a measurement, an activation of the AC measurement voltage at the first frequency via the measurement voltage supply module and to trigger, before the end of the measurement, a deactivation of the AC measurement voltage of the measurement voltage supply module.