The instrumentation of the 600-MW(e) nuclear power station at Stade in the north of the Federal Republic of Germany is a continuation of the line established by that installed in the 340-MW(e) Obrigheim reactor. While basically the Obrigheim instrumentation systems are retained, later operating experience is incorporated, new provisions of the supervisory bodies are met and, as a result of the change-over in power supplies from 220 V a. c. to 24 V d. c. , some new instrumentation series are installed. Real changes are made primarily in the neutron flux instrumentation, both in and out of the core. This paper describes the improvements achieved.