In many industrial sectors one works with gases, vapours, fumes and dusts; in other areas these flammable materials develop during processing. When these are mixed with air and come in contact with a source of ignition an explosion can occur. In order to prevent such dangers and all the resulting damages to the environment, persons and equipment, explosion protection measures were developed. Within the EU, the field of explosion protection is harmonised and regulated through the framework directive 94/9/EC, the so-called ATEX directive, which was passed in 1994.