Ultrasonic

This article treats the ultrasonic in the physical sense. For other meanings see Ultrasonic (term clarifying).

Table of contents

Definition

With Ultrasonic designates one above the human auditory threshold, also between 20 k and 1 GHz. (tones of still higher frequency become than Hypersonic designated, below the sound audible for humans one speaks against it of ).
Ultrasonic waves are flexible, harmonious, three-dimensional, current .
They can spread in gases, liquids and solids. Solids possess form elasticity apart from the volume elasticity additionally. Thus further kinds of wave can occur in solids: those Transverse waves and those Torque shafts.
The transition of airborne sound to solids or liquids takes place only, if the acoustic waves in direct proximity are radiated or a ouple medium of similar acoustic characteristics is between them. Air ultrasonic is reflected or absorbed depending upon material of an obstacle at this (dammed, swallows).

Production

For the production swinging quartz, those are suitable by reversal of the PiezoEffect oscillations become lively. At quartz an alternating voltage with the desired frequency of oscillation is applied. The oscillations become then z.B. transfer to the soil of a cleaning container.

Further there is ultrasonic oscillator on basis soft-magnetic materials. These are based on the effect that Magnetostriction. This effect causes a noticeable change of the expansion (laengsmagnetostriktion) on change of the outside magnetic field. The magnetostrictive transducer material becomes lively by the magnetic alternating field mechanical oscillations. (an effect unwanted within the range of the inductive construction units -- "Trafobrummen")

Applications

Ultrasonic finds in that and various applications:

  • Echolot, Sonar: Tiefenmessung and bottom of the sea investigation from vessels
  • Ultrasonicweld
  • to continuous, contactless Level measurement liquid and firm more differently Consistency and Surface finish
  • Ultrasonic microscope
  • Information transfer; today however with small technical meaning, z.B. in remote maintenance (1970er years) for Television sets or distance measuring equipments.
    • Communication with submarines and underwater devices
  • Testings of materials also Reflectoscopes; over the running time of the signal unintentional inclusions can, Pipe or tears to be discovered
  • Sonografie to the investigation of humans and animal
    • M-mode ("motion mode"), for example to the representation of fetalen heartbeat disturbances
    • B-mode ("brightness mode") to receive around two-dimensional sectional views
    • Doppler: Measurement of the bloodstream speed by means of Doppler effect
    • Color doppler: Colored laminar representation of the bloodstream speed in containers coded,
  • Industrielle divisor agreement up to dissolving, extracting and destroying material in Equipmentdevice devices
  • Ultrasonic cuts (biological fabrics)
  • Ultrasonic engines in Autofocus-Objective one
  • Sputter, atomising, emulsifying and mixing liquids (for example Air moisturizers, Nebula machines)
  • Devices for the deterrence of Mardern (Marderabwehr) and other animals, which are to flee before ultrasonic; an effect could not be proven scientifically so far, yet devices seemed to keep the animals away successfully with a very strong sound club.
  • Dog whistles
  • Applications and Dolphin research, since these orient and/or communicate with itself with ultrasonic
  • The recording of the Ultraschallvokalisation of Rat and mouse (ultrasonic vocalization) is used in the psychopharmakologischen research as also in the neuroscientific behavior research [ 1 ].
  • Also the fragmentation of nephritic stones (Lithotripsie) be based on the effect of short ultrasonic impulses, sucked. acoustic Shock waves.
  • Ultraschallreinigung

See also

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