A thermodynamic method capable of determining the B/A value of 4-ml sample volumes is described. The method involves a procedure in which the static pressure of the sample is altered in a short period of time, to approximate an adiabatic process, during which the ultrasonic velocity is measured. The velocity change so determined is used to calculate the B/A value. The B/A measurement error is l...

Abstract: A pulse-echo technique, based on ultrasonic "long-bar" mode (LBM) velocity measurements, working up to 1700°C is described. Magnetostrictive transducers and ultrasonic lines used in a 40-85 kHz frequency range are detailed. The conditions of choice of fundamental parameters (frequency, line geometry, sample size) are discussed in relation with the nature and the microstructure of ...

The significant difference in the ultrasonic velocity of liquid and solid semiconductors has led to an interest in ultrasonic characterization of anisotropic solid-liquid interfaces during semiconductor single-crystal growth. However, the large solid:liquid velocity ratio could result in potentially severe ray bending at the interface and so detailed ray path and wavefront analyses are needed b...

An ultrasonic transit time flowmeter was tested over Reynolds numbers from 1000 to 100 000 in a calibration facility that generates gas flows with controlled temperature and composition. The gas mixtures were composed of air, nitrogen, carbon dioxide, water vapor, and argon, and the mixture temperature ranged from 290 K to 450 K. The test program was conducted to determine the sensitivity of th...

Among the different non-destructive tests used to carry out an exhaustive survey about the mechanical and durability characteristics of a masonry made of solid tile-bricks, the ultrasonic method has experienced a wide diffusion thanks to its low costs and to its easiness of use; the method essentially consists in detecting the propagation velocity of ultrasonic pulses propagating through a soli...

The subject of the paper is simulation and measurements of an ultrasonic field in an isotropic homogeneous medium with attenuation. The complex problem of simultaneous influence of wave diffraction, attenuation, and velocity dispersion occurs. Only few publications can be mentioned on this subject. For example in [1] is presented an investigation of the complex problem of ultrasound field distr...