Wiring of line and/or double tube plate failure alarm in sodium steam generators

The contact sensor installed in the intermediate space of a double tube plate is connected to an equalizing stage. The equalizing stage is connected via the first amplifier and the first buffer stage to the first encoder with the first signal stage, and via the second amplifier and the second buffer stage to the second encoder with the second signal stage. The first and the second encoders are connected to a ring counter and the contact sensor. The equipment automatically, along one line, differentiates between fail-safe and faulty states of the closed loop and the intermediate space of the double tube plate. (J.P.)