Patent ID: 8011227

Claim:
Apparatus for determining moisture ingress in an insulating layer surrounding a pipe, said insulating layer being surrounded by a tubular jacket, said apparatus comprising an acoustic transducer in communication with an exciter adapted to provide a brief and broad banded acoustic signal which by propagation in the material of the jacket has a wavelength corresponding to twice the thickness of the jacket or an odd multiple part of twice the thickness of the jacket, a signalling processing receiver in communication with the transducer and adapted to receive and process a reverberation signal emitted by the jacket in response to transmitting into the jacket the brief and broad banded output signal from the transducer, wherein the signal processor is adapted to carry out a frequency analysis of the received reverberation signal for producing a frequency response curve, to establish features of the frequency response curve being characteristic of insulation material containing moisture on the inside of the jacket, and to provide an indication being specific to the moisture ingress.