Abstract: A method for detecting faults in plates includes the steps of: transmitting an acoustic signal towards the plate from a transmitting transducer, and receiving the acoustical signal from the plate in a receiving transducer. The receiving transducer is mounted at a distance from the transmitting transducer. The method includes the further steps of identifying zones of the plate wherein energy levels of the received signals are attenuated compared to other zones of the plate, and comparing the energy levels of the A2 and S3 guided Lamb modes in the received signals in the identified zones.

Abstract: It is disclosed a method and device for testing a plate material (1) for the presence of pits and holes (3), said method including the steps of: transmitting an acoustical signal from a transmitting transducer (2) facing the plate material (1) and positioned in a distance from the plate material, the frequency of the transmitted signal and the angle of incidence of the signal towards the plate material being adapted to promote the formation of Lamb signals in the plate material, receiving an acoustical signal returned from the plate material in a receiving transducer (4) also facing the plate material at a distance from the material, the receiving transducer (4) being located in a distance from said transmitting transducer (2) along the direction of the plate material, time gating the received signal identifying a tail part (8) carrying information from Lamb signals travelling in the material, and determining the energy content in said Lamb mode part of the signal.

Abstract: A method for detecting faults in plates includes the steps of: transmitting an acoustic signal towards the plate from a transmitting transducer, and receiving the acoustical signal from the plate in a receiving transducer. The receiving transducer is mounted at a distance from the transmitting transducer. The method includes the further steps of identifying zones of the plate wherein energy levels of the received signals are attenuated compared to other zones of the plate, and comparing the energy levels of the A2 and S3 guided Lamb modes in the received signals in the identified zones.

Abstract: It is described an apparatus for inspecting a pipeline, said apparatus including a cylindrical body (15) adapted to be transported inside said pipeline, an array of acoustical transducers (Tx,y) installed in the surface of the cylindrical body (15), the acoustical transducers being organized in columns and rows in a belt around the cylindrical body, a controller adapted to initiate a transmission of an acoustical signal from a first transducer (T2,2) and a reception of said acoustical signal from other transducers in said array surrounding the first transducer, the controller further being adapted to determine the direction to a flaw in the wall of said pipeline from the received acoustical signals.

Abstract: An apparatus and method for measuring the internal pressure of a pipe or container is disclosed. The apparatus includes an acoustical transmitter (Tx1) mounted on a wall (1) of said pipe or container and a signal generator (2) connected to said transmitter and which is adapted to provide a signal to the transmitter. The signal from the transmitter is detected by two receivers (Rx1, Rx2) mounted on said pipe or container in a distance from said transmitter (Tx1). A processing unit (3) is connected to said transmitter and receivers, the processing unit being adapted to measure the travel time of an acoustical signal propagating between two receivers in the wall (i) and determine the pressure inside the pipe or container from said travel time.

Abstract: It is described an apparatus for inspecting a pipeline, said apparatus including a cylindrical body (15) adapted to be transported inside said pipeline, an array of acoustical transducers (Tx,y) installed in the surface of the cylindrical body (15), the acoustical transducers being organized in columns and rows in a belt around the cylindrical body, a controller adapted to initiate a transmission of an acoustical signal from a first transducer (T2,2) and a reception of said acoustical signal from other transducers in said array surrounding the first transducer, the controller further being adapted to determine the direction to a flaw in the wall of said pipeline from the received acoustical signals.

Abstract: An apparatus and method for measuring the internal pressure of a pipe or container is disclosed. The apparatus includes an acoustical transmitter (Tx1) mounted on a wall (1) of said pipe or container and a signal generator (2) connected to said transmitter and which is adapted to provide a signal to the transmitter. The signal from the transmitter is detected by two receivers (Rx1, Rx2) mounted on said pipe or container in a distance from said transmitter (Tx1). A processing unit (3) is connected to said transmitter and receivers, the processing unit being adapted to measure the travel time of an acoustical signal propagating between two receivers in the wall (i) and determine the pressure inside the pipe or container from said travel time.

Abstract: An acoustic apparatus adapted to operate in a gas filled space from a first side of an object to be measured for making a non-contact thickness measurement thereof includes an electro acoustic transducer, a transceiver coupled with the electro acoustic transducer and adapted to excite electro acoustic transducer to output an acoustic signal towards the object to be measured and receive an acoustic response signal therefrom, and a signal processor adapted to process the response signal and determine a thickness of the object. The electroacoustic transducer has a transducer-to-gas acoustic interface, and the transceiver is adapted to operate the electroacoustic transducer so as to emit into a gas filled gap an acoustic broad band pulse towards the object and to receive an acoustic resonance response signal in the acoustic response signal at a level that allows acquisition of the resonance response signal above a predetermined signal to noise level.

Abstract: An apparatus and a method for determining a moisture ingress in an insulating layer surrounding a pipe, the insulating layer being surrounded by a tubular jacket. The apparatus includes an acoustic transducer in communication with an exciter adapted to provide a brief and broad banded acoustic signal which includes frequencies which by their propagation in the material of the jacket has a wavelength which corresponds to twice the thickness of the jacket or an odd multiple of twice the thickness of the jacket, and to process a reverberation signal emitted from the jacket in response to sending into the jacket the brief and broad banded output signal from the transducer.

Abstract: An acoustic apparatus adapted to operate in a gas filled space from a first side of an object to be measured for making a non-contact thickness measurement thereof includes an electro acoustic transducer, a transceiver coupled with the electro acoustic transducer and adapted to excite electro acoustic transducer to output an acoustic signal towards the object to be measured and receive an acoustic response signal therefrom, and a signal processor adapted to process the response signal and determine a thickness of the object. The electroacoustic transducer has a transducer-to-gas acoustic interface, and the transceiver is adapted to operate the electroacoustic transducer so as to emit into a gas filled gap an acoustic broad band pulse towards the object and to receive an acoustic resonance response signal in the acoustic response signal at a level that allows acquisition of the resonance response signal above a predetermined signal to noise level.

Abstract: An acoustic apparatus adapted to operate in a gas filled space from a first side of an object to be measured for making a non-contact thickness measurement thereof includes an electro acoustic transducer, a transceiver coupled with the electro acoustic transducer and adapted to excite electro acoustic transducer to output an acoustic signal towards the object to be measured and receive an acoustic response signal therefrom, and a signal processor adapted to process the response signal and determine a thickness of the object. The electroacoustic transducer has a transducer-to-gas acoustic interface, and the transceiver is adapted to operate the electroacoustic transducer so as to emit into a gas filled gap an acoustic broad band pulse towards the object and to receive an acoustic resonance response signal in the acoustic response signal at a level that allows acquisition of the resonance response signal above a predetermined signal to noise level.

Abstract: An acoustic apparatus adapted to operate in a gas filled space from a first side of an object to be measured for making a non-contact thickness measurement thereof includes an electro acoustic transducer, a transceiver coupled with the electro acoustic transducer and adapted to excite electro acoustic transducer to output an acoustic signal towards the object to be measured and receive an acoustic response signal therefrom, and a signal processor adapted to process the response signal and determine a thickness of the object. The electroacoustic transducer has a transducer-to-gas acoustic interface, and the transceiver is adapted to operate the electroacoustic transducer so as to emit into a gas filled gap an acoustic broad band pulse towards the object and to receive an acoustic resonance response signal in the acoustic response signal at a level that allows acquisition of the resonance response signal above a predetermined signal to noise level.

Abstract: An apparatus and a method for determining a moisture ingress in an insulating layer surrounding a pipe, the insulating layer being surrounded by a tubular jacket. The apparatus includes an acoustic transducer in communication with an exciter adapted to provide a brief and broad banded acoustic signal which includes frequencies which by their propagation in the material of the jacket has a wavelength which corresponds to twice the thickness of the jacket or an odd multiple of twice the thickness of the jacket, and to process a reverberation signal emitted from the jacket in response to sending into the jacket the brief and broad banded output signal from the transducer.