Abstract: A device for detecting a medium includes a sensor hose to be laid at a medium to be detected. A material is disposed at least in the vicinity of the sensor hose. The material reacts when in contact with the medium to be detected to produce a substance being capable of diffusion and being detectable.

Abstract: A device for sealing off and monitoring a volume includes two seals. Support elements space the seals apart from one another. At least one conduit is disposed between the seals and the support elements. The at least one conduit has an inlet opening and an outlet opening for a medium. At least one sensor is associated with the outlet line. The two seals have edges being tightly joined to one another leaving the inlet and outlet openings of the at least one conduit free. The support elements are formed of a flow-hindering material. At least two devices may be tightly joined together to form a field, with the outlet opening of the at least one conduit of one of the at least two devices being connected to the inlet opening of the at least one conduit of another of the at least two devices.