A measuring device comprising a sensor for the high frequency detection of a measurement variable, such as sound, structure-borne noise, current, voltage, optical or magnetic measurement values and the like, with an operator network comprising at least one operator. An operator network that includes a notification operator, a machine control operator and/or a difference operator. The devices can be configured to identify events in a material-processing and/or material production process on the basis of a multidimensional data stream obtained during the process and having temporally resolved frequency and energy information, and to the use of defect patterns and/or event patterns and/or energy data, the data being supplied to a pattern operator or multiple pattern operators arranged in parallel or one after the other.