It is provided an apparatus for determining at least one of physical, chemical and biological properties of a medium, comprising an acoustic waveguide, which has a conduction element with an inner side that faces the medium and an outer side that lies opposite this inner side. The inner side facing the medium is curved in concave fashion and the outer side is curved in convex fashion and the waveguide with the conduction element curved in that way is configured such that a second surface wave coupling-in at the concave inner side propagates along a propagation direction to the receiver. At least one damping element lies downstream of the receiver in the propagation direction of the second surface wave, said damping element being arranged and configured to prevent surface waves propagating counter to the propagation direction of the at least one second surface wave from reaching the receiver.

A nondestructive inspection apparatus includes a focused ultrasonic probe which transmits burst waves to a surface of a spherical body in water, a signal output portion which outputs the burst waves to the focused ultrasonic probe, a probe position changing mechanism which rotates the spherical body arranged in water so as to change a position at which the burst waves from the focused ultrasonic probeare incident, and a signal detection portion which detects a harmonic waveform generated when a closed crack or a metal inclusion oscillates by waves excited in the spherical body by the burst waves through mode conversion. A closed crack or a metal inclusion in the vicinity of a surface of the spherical body can thus be detected and imaged as necessary.

A spherical body inspection apparatus including a support arrangement realized to support a spherical body during an inspection procedure; a probe arrangement comprising a plurality of UT probes arranged about the spherical body such that the UT probes target a common test point at the surface of the spherical body; and a displacer for effecting at least one relative rotational displacement between the spherical body and the probe arrangement. Also described is a method of inspecting a spherical body.

A device for determining properties of a medium has a hollow body which accommodates the medium and a housing which circumferentially surrounds the hollow body. At least one portion of a wall of the hollow body is formed as waveguide for acoustic surface waves, which forms an interface to the medium. There is provided at least one transmitter for exciting acoustic waves in the waveguide and at least one receiver for receiving acoustic waves from the waveguide, which are arranged at a distance from each other, wherein the transmitter and the receiver are in direct contact with an outer surface of the waveguide and wherein the distance between transmitter and receiver is chosen such that acoustic waves excited by the transmitter can at least partly propagate on paths extending through the medium. There is provided at least one contact carrier on which the transmitter and/or the receiver are arranged. Between the waveguide and the contact carrier a continuous air gap is formed. The space between the hollow body, the contact carrier and the housing is filled with a filling mass.

The present invention provides a mode conversion reflector provided on an edge surface of an elastic medium, capable of mode-converting an incident ultrasonic wave with high efficiency and simultaneously reflecting the wave in a desired direction. The mode conversion reflector according to the embodiment includes an elastic medium; and a reflective layer formed of a non-planar structure on an edge surface of the elastic medium, in which an interference phenomenon caused by diffraction of wave occurs by the reflective layer, so that an ultrasonic wave incident through the elastic medium is mode-converted and reflected in a predetermined direction.

Ultrasonic excitation to a sample is provided with an apparatus including: a cylindrical ultrasonic transducer, and a plate disposed on an end of the cylindrical ultrasonic transducer. The ultrasonic transducer is configured to provide a vertical vibration in operation. A Lamb wave vibration is generated in the plate by the vertical vibration of the ultrasonic transducer. The Lamb wave vibration converges at a central region of the plate, where a sample is disposed. Alternatively, a cylindrical array of ultrasonic transducers can be used instead of a single cylindrical transducer. Such an array can be driven as a phased array for beam shaping and/or multi-focusing.