Abstract: A measuring routine for monitoring the operating state of a fuel cell arrangement consisting of at least one fuel cell, in which the fuel cell arrangement has an operating load connected to it, at least one power amplifier for supplying at least one low-frequency signal (se1(t), se2(t)) is further provided, the output of which is coupled to the fuel cell arrangement, and having an evaluation device, likewise coupled to the fuel cell arrangement, for capturing a signal response sai(t) to the at least one supplied signal sei(t), wherein the fuel cell arrangement (1) has two or more individual signals (se1(t), se2(t)) at different frequencies (fe1, fe2) supplied to it and the evaluation device is set up to capture the signal response sai(t) for selected frequencies (fa3, fa4) of the intermodulation products (mfe1+/?nfe2) of the supplied individual signals (se1(t), se2(t)) and to measure at least the amplitude of said signal response in order to obtain at least one output signal (SAZ, S?AZ, S?AZ).

Abstract: A measuring routine for monitoring the operating state of a fuel cell arrangement consisting of at least one fuel cell, in which the fuel cell arrangement has an operating load connected to it, at least one power amplifier for supplying at least one low-frequency signal (se1(t), se2(t)) is further provided, the output of which is coupled to the fuel cell arrangement, and having an evaluation device, likewise coupled to the fuel cell arrangement, for capturing a signal response sai(t) to the at least one supplied signal sei(t), wherein the fuel cell arrangement (1) has two or more individual signals (se1(t), se2(t)) at different frequencies (fe1, fe2) supplied to it and the evaluation device is set up to capture the signal response sai(t) for selected frequencies (fa3, fa4) of the intermodulation products (mfe1+/?nfe2) of the supplied individual signals (se1(t), se2(t)) and to measure at least the amplitude of said signal response in order to obtain at least one output signal (SAZ, S?AZ, S?AZ).