The invention relates to a measuring apparatus for characterizing the electrical resistance of a measurement object, comprising an electric energy source having two poles, a voltage measuring device having two measuring inputs, four connecting contacts for the connection of four contact electrodes, and a switching device for the variable electrical pairwise connection of each one of the poles and measuring inputs to each one of the connecting contacts, forming different wiring configurations, wherein the measuring device is configured to carry out at least two measuring sequences with different wiring configurations and to determine the series resistance of the measurement object by incorporating the current and voltage signals acquired in these wiring configurations.