Especially intensive interference fields are produced, for example, in microwave drying, by electrical discharge machining systems and by high-frequency welding equipment.
In such cases, the standard Rittal enclosures and housings are often no longer adequate. It is recommended instead to employ a special Rittal EMC enclosure:
Shielding against external interference fields 
Shielding against emitted interference fields
High shielding effect - how it's done
A practically unbroken electroconductive connection is achieved between the outer surfaces of the housing by fitting a special conductive seal. The inner surfaces and the seal edges remain unpainted. Corrosion protection is provided by the aluminium-zinc coating of the base material.
The quality of a housing in practical use can only be as high as the quality of its original manufacturing!
The integrity of the shielding must also be taken into account where cut-outs are made for inspection windows or climate control components (shielded panes, wire mesh, honeycomb cells).
How the level of shielding is represented:
enlarge picture- In the shield attenuation diagram, the weakening of the fields by the housing is plotted against the frequency on a logarithmic scale.
- 20 dB shield attenuation corresponds to a weakening by the factor 10
- 40 dB shield attenuation corresponds to a weakening by the factor 100
- 60 dB shield attenuation corresponds to a weakening by the factor 1000 and so on.
The diagrams are based on shield attenuation measurements performed in accordance with relevant testing regulations (MIL-STD 285, VG 95 373 Part 15).