Abstract: An active protective circuit for a measuring amplifier of an electrical impedance tomograph includes a circuit component arrangement including an electrode input and an output and a control input for a control voltage. The output is configured for connection to a measuring amplifier for an electrical impedance tomograph. The circuit component arrangement creates a conductive connection between the electrode input of the circuit component arrangement and the output of the circuit component arrangement when the applied control voltage is within a first voltage range and does not create a conductive connection when the applied control voltage is within a second voltage range. The voltage being applied to the control input is within the second voltage range when a voltage, which is within a cut-off range, is applied to the electrode input. An electrode belt for impedance tomography has the active protective circuits associated with the electrodes.