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 method for determining the location of a leak in pressure-carrying vessels, including a plurality of probes spaced-apart on walls of the vessels for picking up high-frequency solid-conducted sound noises, and an amplifier connected to the probes, includes forming an r.m.s. value in the amplifier from the sound noises, comparing the r.m.s. value with a threshold value, issuing a signal if the r.m.s. value exceeds the threshold value, comparing the solid-conducted sound noises from at least two probes with each other for localizing the leak, placing the r.m.s. values of the solid-conducted sound noises in a relationship relative to the spacing between the probes based on the comparison, and determining the location of the leak as the location of the maximum solid-conducted sound noise from the relationship.