Abstract: An apparatus for detecting a leak in the storage tank which includes a transducer for detecting and converting a mechanical wave into an electrical signal, a support tube having an upper end extending outside of the tank and a lower end extending inside the tank into the fluid medium. The transducer is affixed to the lower end of the support tube. A signal processing unit for processing the electrical signal, and electrical cable for transmitting the electrical signal from the transducer to the signal processing unit is also present. A method of using the apparatus is also provided.

Abstract: A method and apparatus for detecting the presence of surface corrosion under insulation on a piping structure employs artificially generated, broadband acoustic sound waves to interrogate the piping structure. The sound waves are coupled into the piping structure and detected after they have propagated through and interacted with a portion of the piping structure. The amplitude of RMS voltage signals indicative of the detected sound waves is used to determine whether or not surface corrosion is present. Highly corroded pipes have been shown to yield relatively low RMS voltage signals whereas the lack of corrosion yields relatively high RMS voltage signals.

Abstract: An apparatus and method are disclosed for determining the integrity of coated fuel particles via acoustic characterization. Particle supply means (4) drops the nuclear fuel particles (2) individually onto the face (6) of a transducer (8). The generated signal which is indicative of the integrity of the coating on the dropped particle is analyzed with analyzing means (26, 28, 30) for discriminating between a flawed and an unflawed particle.

Abstract: An acoustic emission leak simulator (10) for a nondestructive simulation of a leak in a structure employs a fluid supply with variable orifice (18) for controllably releasing the fluid to create a simulated leak source (20). An acoustic waveguide (22) acoustically coupled to the variable orifice (18) couples the sound waves into the structure (12) for simulation of a leak signal. Transducer (30) positioned at a predetermined distance from the simulated leak source (20) characterize the leak signals for a leak detection system.

Abstract: A method for inspecting the surface of a workpiece for the presence of flaws using a ferrofluid as a penetrant which is applied to the surface of the workpiece and then scanning the surface of the workpiece with electrical detection means placed adjacent to the surface for providing responses indicative of the presence of flaws in the surface of the workpiece. If desired, a magnetic field can be used to induce the flow of the ferrofluid into any flaws prior to inspection, and for post-inspection cleanup as well. By the use of a ferrofluid, the sensitivity of the electrical detection means, advantageously of the eddy current type, is enhanced in typical applications, and also allows the use of an eddy current probe to inspect workpieces made of nonconductive and/or nonferromagnetic materials.

Abstract: A method and apparatus for locating a leak which produces a continuous acoustic emission having background noise and spikes, comprises continuously monitoring the acoustic emissions using spaced apart detectors which produce signals having background noise and spikes corresponding to those of the continuous acoustic emissions. The spikes of one signal are offset in time with respect to the spikes of the other signal, which corresponds to the difference in travel time of the acoustic signals to each of the detectors. By measuring the offset between the spikes, the relative position of the acoustic emission, and thus the relative position of the leak, can be determined with respect to the position of the detectors. To facilitate separating the spikes from the background noise, a floating detection threshold value is applied to the signals for eliminating the background noise.