1. Ultrasonic testing. Shorter than ordinary sound waves, wave lengths of ultrasound make a good direction, but also through the opaque material, this feature has been widely used in ultrasonic testing, thickness, distance measurement, remote control and the technology of ultrasonic imaging. Ultrasonic imaging is a technology that USES ultrasound to present the inner image of opaque objects. From the transducer of ultrasonic acoustic lens focused on opaque sample, the ultrasonic carried from the sample passes was as part of the information (such as the ability of reflection, absorption and scattering of sound waves), the acoustic lens converge on piezoelectric receiver, the electrical signal input amplifier, using scanning system can turn opaque sample image displayed on the screen. The device is called an ultrasonic microscope. Ultrasonic imaging technology has been widely applied in medical examination, in the manufacturing of microelectronic device used for inspection on large scale integrated circuit, is used for displaying alloys of different compositions in the materials science area and grain boundary, etc. Acoustical holography is an ultrasonic interference principle of record and reproduce the three-dimensional image of opaque acoustic imaging technology, its principle and optical holography are basically the same, just record means different (see holography). With the same ultrasonic signal source motivation two transducer be placed in a liquid, they launched two coherent beam of ultrasound: a beam through the object studied after become a wave, a bunch of reference wave. Object wave and reference wave coherent superposition acoustical hologram formed on the surface of the liquid, with laser beam acoustical hologram, using a laser reflection on acoustical hologram diffraction effect and get things back like, usually with a camera and television sets for real-time observation.
2. Ultrasonic treatment. Using ultrasonic mechanical action, cavitation effect and heat effect and chemical effect, ultrasonic welding, drilling, the solid can be shattered, emulsification, degassing, dust removal, to scale, cleaning, sterilization, and promote chemistry and biology, etc., in GongKuangYe, agriculture, medical departments received a wide range of applications.
3. Basic research. When ultrasonic wave ACTS on the medium, producing acoustic relaxation process in the medium, acoustic relaxation process with electrical degrees between respectively for the molecular energy transport process, and to absorb sound waves in the macro (see sound waves). The characteristics and structures of substances can be explored through the absorption law of substances to ultrasound, which constitutes the branch of molecular acoustics. The wave of ordinary sound waves is longer than the distance between atoms in the solid, under which the solid can be regarded as a continuous medium. However, for ultrasonic waves with frequencies above 1012 hz, the wavelength can be compared with the spacing between atoms in the solid. At this time, the solid must be regarded as a point matrix structure with spatial periodicity. The energy of lattice vibration is quantized and is called phonon (see solid physics). The effects of ultrasound on solids can be summarized as the interactions between ultrasound and thermophonons, electrons, photons and various quasiparticles. The study on the generation, detection and propagation of special ultrasound in solids, as well as the study on the sound phenomenon in quantum liquids -- liquid helium, constitute a new field of modern acoustics