Methods for quantitatively determining the time (TNI) between (1) the application of this method and (2) the time at which the next out-of-service API 653 internal inspection of a steel, field-erected, aboveground storage tank (AST) containing petroleum/water products should be performed. These methods combine four in-service measurements of the thickness, integrity, and corrosion rate of the tank bottom with an empirical corrosion rate cumulative frequency distribution (CFD) for the tank of interest to develop a Bayesian tank bottom survival probability distribution to determine TNI. During this entire TNI time period, the risk of tank bottom failure is less than at the time these methods were applied. If available, the results of a previous out-of-service API 653 internal inspection are also used. These methods can be applied at any time while the tank is in-service to update the internal inspection interval previously determined in an out-of-service internal inspection of the tank.

A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.

Acoustic transducers generate and receive acoustic signals at multiple locations along a surface of rigid structure, wherein longitudinal spacing between transducer locations define measurement zones. Acoustic signals with chosen amplitude-time-frequency characteristics excite multiple vibration modes in the structure within each zone. Small mechanical changes in inspection zones lead to scattering and attenuation of broadband acoustic signals, which are detectable as changes in received signal characteristics as part of a through-transmission technique. Additional use of short, narrowband pulse acoustic signals as part of a pulse-echo technique allows determination of the relative location of the mechanical change within each zone based on the differential delay profiles. For accurate acoustic modeling and simulation, the mesh size, time step, time delay, and time-window size are optimized. Frequency normalization of the Short-Time Fourier Transform of acoustic response output improves experiment-simulation cross-validation. Applications of the method to structures with arbitrarily complex geometries are also demonstrated.

A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.

A system and method is disclosed for calibrating the volume of storage containers using mechanical or acoustic wave-based inspection techniques. The exemplary calibration system comprises an array of measurement devices controllably deployed in respective positions on the outside surface of the container. The measurement devices include a transducer for sending signals along the surface of the container and sensors configured to detect the signals. The measurement devices are in communication with a diagnostic computing device that controls the positioning and the operation of the measurement devices and is further configured to determine the time time-of-flight of the signals that travel between the various devices. Moreover, according to the specific arrangement of the measurement devices and the measured signal information, the control computer is configured to calculate the dimensions of the container and its internal volume.

A non-destructive inspection judgment system for inspecting a non-destructive inspection subject using ultrasonic waves, including an ultrasonic wave generator transmitting and receiving ultrasonic signals by generating ultrasonic waves to the non-destructive inspection subject placed on an inspection table, an interface transmitting an ultrasonic signal received from the ultrasonic wave generator to an ultrasonic wave generation data controller, the ultrasonic wave generation data controller processing ultrasonic wave data received from the interface, a sealing defect presence judger determining, using the processed ultrasonic wave data, whether a sealing defect is present, and a display displaying a result of the judgment on a monitor to detect an unsealed portion of an aluminum pouch.

A method of performing a selected task in a tank containing an energetic substance uses an inherently safe mobile platform that includes a marker detector, a control unit, a power supply, a propulsion system, and an inherently safe enclosure. The inherently safe enclosure prevents a spark occurring inside the inherently safe enclosure from passing to an exterior of the inherently safe enclosure. All spark-generating components of the mobile platform are positioned inside the inherently safe enclosure. The method includes lowering the mobile platform into the tank, at least partially submerging the mobile platform in the energetic substance, and detecting a marker using the marker detector. No active physical carrier connects the mobile platform to an object exterior of the tank while the mobile platform is in the tank.

A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.

Embodiments of the present invention provide systems and methods for tagging and acoustically characterizing containers.

A holding arrangement for holding an acoustic transmitter in place in relation to a container. The arrangement comprises: a body comprising a cavity for holding an acoustic transmitter, the cavity comprising an opening arranged to face said container when said arrangement is attached to a container, wherein the body comprises acoustic damping material, and wherein the cavity is configured to permit movement of an acoustic transmitter in a direction perpendicular to a container surface and to restrict movement of the acoustic transmitter in directions not perpendicular to the container surface when an acoustic transmitter is arranged in said cavity and when said arrangement is attached to a container. There is also provided a measurement arrangement comprising such a holding arrangement.