Ultrasonic pulse-echo methods are versatile, effective procedures for inspecting welds in steel structures. However, the ultrasonic methods conventionally used have two disadvantages: inspection must be performed manually by a skilled technician, and the signal obtained at the time of one inspection provides no “memory” to be used at the time of a later inspection. Our research involves the dev...

This paper proposes a continuous leakage location method based on the ultrasonic array sensor, which is specific to continuous gas leakage in a pressure container with an integral stiffener. This method collects the ultrasonic signals generated from the leakage hole through the piezoelectric ultrasonic sensor array, and analyzes the space-time correlation of every collected signal in the array....

Ultrasonic phased arrays will eventually replace conventional ultrasonic methods in many nondestructive evaluation (NDE) applications. However, the transition to phased arrays is not without its pitfalls and challenges. In this report we present a summary of the advantages and limitations of phased-array ultrasonics in NDE, with specific reference to the inspection of thicksection welds. The ma...

Partial discharge (PD) is the main cause of electric equipment degradation. PD location can provide the scientific direction and analysis for equipment condition monitoring. The phased-ultrasonic receiving-planar array transducer for PD location in transformer is studied in this paper. The operation environment and material properties of transducer are analyzed. The center frequency of transduc...

The crosstalk in multichannel simultaneously triggered ultrasonic sensors of ultrasonic ranging system may cause false measurement. This paper presents pseudorandom digital modulation excitation sequences for multichannel ultrasonic sensors to avoid crosstalk. To make full use of bandwidth of the ultrasonic sensors, the parameters of the pseudorandom digital modulation methods are configured. A...

This work investigates a strongly-focused annular array for high frequency ultrasonic applications, offering improved resolution without increasing the operating frequency, potentially reducing the complexity of manufacture. However, the conventional geometry, specifically the Equal Area array exhibits a problem with high sidelobes. A method based on geometric change is developed to control the...

We report a transducer structure tha t combines two orthogonal phased arrays which enable the real-time scanning of two orthogonal sectors. This biplane phased array is formed by partially dicing the opposite faces of a composite piezoelectric plate in orthogonal directions. Individual elements of the orthogonal arrays show broad radiation patterns close to the theoretical expectations for isol...

An investigation into the development of an ultrasound imaging system capable of customization for multiple applications via the tessellation of in-system programmable scalable modules, or tiles, is presented here. Each tile contains an individual ultrasonic array, operating at +/-3.3V, which can be assembled into a larger ‘mosaic’ of multiple tiles to create arrays of any size or shape. The ab...

Modern ultrasound scanners use large either linear or phased array of piezoelectric transducers. Design principle of electronic beamforming networks thus draws heavily from that of adaptive antenna array. However, the interaction of ultrasound with human tissue appears to be much more complicated than that of the electromagnetic wave. While with Xrays we get a shadow image of the system, with u...

Interference between sensors is a serious problem when ultrasonic sensor arrays are used to monitor and to explore the environment. In ultrasonic sensor arrays operating in the pulse-echo mode, the transmitters usually are excited serially by time division multiplexing. The repetition rate of the entire system is limited by the time of flight (TOF) of the pulses. For in-room applications, the T...