Abstract: A device for measuring condensation and/or advance of corrosion of a conduit includes an insulator extending around the conduit; a first conductor and a second conductor which are arranged such that at least a portion of the insulator lies between the conduit and the first conductor and the second conductor, such that the first conductor forms a first pole of a capacitor, the second conductor forms a second pole of the capacitor, and the portion therebetween comprises a capacitive coupling between the first pole and the second pole. At least one measuring instrument is configured to determine a value which is representative of the capacitive coupling.