The inventive device includes a first shell holder for fixing a first shell, a second shell holder for fixing a second shell, a first support on which the first shell holder is mounted and a second support on which the second shell holder is mounted, the first and second supports being pivotable with respect to each other. At least one quantitative quality indicator is automatically determined for at least one of the samples, and the digital image of the magnified portion of the sample. The aim of the invention is to improve a method and device of the aforementioned type such that the extinguishing agent is variably and selectively discharged with a high degree of efficacy by the provision of a system which can be modularly integrated in the security design of a building. At least one first and one second rotary coupling piece are accessible from the outsides of a casing of the mitre gear unit and are provided for connecting the angle drive to two further mitre gear units for driving in each case one adjacent roller. The film can be produced by thermoplastic processes or solvent cast processes. The controller and associated sensors function to assure that sufficient charge passes through conductors applied to the body of the vehicle to maintain cathodic protection on a consistent basis.