Abstract: The limit values for the field strengths of emitted electromagnetic interference fields from electronic appliances and modules (BG1, BG2) are defined in guidelines, for example for communications devices in the regulation NEBS Level 3. Together with the limit values, the operating conditions are also always defined, in which the limit values must not be exceeded. For example, there is a requirement for the limit values to be complied with even during servicing, in which both the rack door and the door of the module shelf or module frame (T) are open. The appropriate limit values are regularly not complied with by existing systems when the door of the module shelf or module frame (T) is open, if, for example, the modules (BG1, BG2) of the existing systems are equipped with plastic shutters (2).