A connection unit (1) connects an impedance tomograph (3) electrically to first and second skin electrodes (6, 8). The skin electrodes (6, 8) are arranged on an electrode carrier (4) spaced from one another in a longitudinal direction L. First and second opposite contact devices (24, 26) are arranged on the electrode carrier (4) and are respectively connected to associated electrodes (6, 8). First and second contact devices (16, 18) are configured for respective detachable connection to the associated first and second opposite contact devices (24, 26). Each contact device (16, 18) has an electric protective circuit (10, 12). A system is provided for an electrical impedance tomograph (3), which system has the connection unit (1).
