METHOD FOR DETERMINING AN OPERATING STATE OF AN ELECTROCHEMICAL SYSTEM

The invention relates to a method for determining an operating state of an electrochemical system (1; 1; 1; 1; 1), which has a cell stack () having at least one electrode portion (), at least one valve () and at least one fluid line () being provided, the method comprising the following steps: conducting, in a varying manner, at least one fluid through the at least one valve () via the at least one fluid line () with a predefined variation pattern, the variation pattern being applied to a fluid flow by means of the at least one valve (), determining a voltage response and/or a current response of the cell stack () during the varying conducting of the at least one fluid, and determining the operating state of the electrochemical system (1; 1; 1; 1; 1) on the basis of the voltage response and/or the current response. The invention further relates to a computer program product (), to a storage means (), to a circuit assembly () and to an electrochemical system (1; 1; 1; 1; 1).