Abstract: A method and apparatus for fixing an instantaneous measured value performs the steps of creating measured values as a mean value of a set number of individual measurements, recording sequential measured values after initialization in a cycle determined by a flow control, checking with a control device if a new measured value exceeds a base value and if the difference between the two latest measured values lies within a given limit range, before fixing the respective new measured value, and checking with the control device if the difference between the individual values resulting from the latest two individual measurements lies within the given limit range and if a fixing of the last measured value and/or individual value takes place when the differences between the mean values and the differences between the individual values lie in the respective given limit range.