Abstract: The invention is directed to a measuring apparatus for determining the degree of compaction of material for building dams, roads or the like after the material has been compacted with a suitable compaction machine. The measuring apparatus includes a vibrating drum which is equipped with a transducer for generating signals while the drum is run over the ground surface for which the degree of compaction is to be determined. In order to eliminate factors which impede evaluation of the signals emanating from the signal transducers, the drum is configured so that its contact surface with the ground surface is as restricted as possible. This can be achieved by reducing the width of the drum.

Abstract: A method and a device for the purpose of de-icing those covers and other surfaces of limited size which can be subjected to severe icing and which it may be necessary to make ice-free at very short notice. Examples of the types of surfaces intended are protective doors for ship-borne missiles and torpedo tubes, emergency exit doors, and helicopter landing platforms etc. These surfaces are de-iced by an interior igniting primed tubular power charge which in the case of doors is placed directly in a groove along edges which the door seals against the surrounding door frame or another mating door, and in the case of other types of surfaces is placed in accordance with a pattern intended for that particular surface. The tubular powder charge is placed in an open groove in the relevant surface which faces in the same direction as it is desired that the ice should be flaked loose.