An ultrasonic technique, invariant to temperature changes, for a density measurement of different liquids under in situ extreme conditions is presented. The influence of geometry and material parameters of the measurement system (transducer, waveguide, matching layer) on measurement accuracy and reliability is analyzed theoretically along with experimental results. The proposed method is based ...

This work demonstrates a novel application of ultrasound: measurement of magnetostriction, the change of length of a ferromagnetic material that accompanies a change in magnetization. The technique involves measuring ultrasonic waves generated by an electromagnetic acoustic transducer (EMAT), and it offers an alternative method of measuring magnetostriction in cases where it would not be feasib...

A 1 × 16 capacitive micro-machined ultrasonic transducer linear array was designed, fabricated, and tested for underwater imaging in the low frequency range. The linear array was fabricated using Si-SOI bonding techniques. Underwater transmission performance was tested in a water tank, and the array has a resonant frequency of 700 kHz, with pressure amplitude 182 dB (μPa·m/V) at 1 m. The -3 dB ...

Abstract: A significant challenge in nondestructive evaluation is the ability to discern signals, originating from a crack and a geometric feature in a part, that are either closely spaced or superimposed in time. An example problem is the ultrasonic inspection of aircraft holes in vertical riser structures with limited accessibility for a transducer from an external wing surface. Characteristi...

Focusing an ultrasonic surface or bulk wave to a point can maximise the amount of ultrasonic energy at a point and increase the sensitivity of a measurement. Using noncontact ultrasonic methods we focus an ultrasonic wave pulse on or in a sample. Focusing can be achieved by using a shaped source or by the surface profile of the sample itself. Experiments and modelling confirm the known result t...

In order to work at higher ultrasonic frequencies, for instance, to increase the resolution, it is necessary to fabricate smaller and higher frequency transducers. This paper presents an ultrasonic transducer capable of being made at a very small size and operated at GHz frequencies. The transducers are activated and read optically using pulsed lasers and without physical contact between the in...

Near-field ultrasonic response (50-2000 kHz) of an underwater 1-3 piezocomposite transducer is experimentally investigated using a polarimetric polarization maintaining fiber sensor. Measured outputs from our sensor and a reference hydrophone are observed to be comparable.

We present the results of experimental investigation of ultrasonic washing of textiles. The results demonstrate that cavitation bubbles oscillating in acoustic fields are capable of removing soils from textiles. Since the washing performance is mitigated in a large washing bath when using an ultrasonic transducer, we propose a novel washing scheme by combining the ultrasonic vibration with a co...

The broadband narrow pulse self-focusing ultrasonic transducer was designed for the special structure of the column holes, and used to do the research for the testing of bonding layer of metal composite material with F-scan ultrasonic imaging system. The copper-steel boding layer of bimetal rotor is connected by diffusing welding. There may be delamination flaws existed here. The depth and rang...

Ultrasonic measurements of materials are usually obtained from an electrical conversion of an acoustic signal by a transducer. ln this paper, a conventional (phase sensitive) transducer and a new phase insensitive acoustoelectric converter called an AEC are contrasted. In particular, the AEC is shown to exhibit superior characteristics for many typical experi~nts and appears to have many applic...