40/80khz Transducers Cleaning Cavitation Ultrasonic Piezo Transducer
40/80khz Transducers Cleaning Cavitation Ultrasonic Piezo Cleaning
In order to understand the mechanics of ultrasonics, it is necessary to first have a basic understanding of sound waves,
how they are generated and how they travel through a conducting medium. The dictionary defines sound as
the transmission of vibration through an elastic medium which may be a solid, liquid, or a gas.
Sound Wave Generation A sound wave is produced when a solitary or repeating displacement is generated
in a sound conducting medium, such as by a “shock” event or “vibratory” movement. The displacement of air
by the cone of a radio speaker is a good example of “vibratory” sound waves generated by mechanical
movement. As the speaker cone moves back and forth, the air in front of the cone is alternately compressed
and rarefied to produce sound waves, which travel through the air until they are finally dissipated.
We are probably most familiar with sound waves generated by alternating mechanical motion.
There are also sound waves which are created by a single “shock” event. An example is thunder
which is generated as air instantaneously changes volume as a result of an electrical discharge (lightning).
Another example of a shock event might be the sound created as a wooden board falls with its face against
a cement floor. Shock events are sources of a single compression wave which radiates from the source.
The Nature of Sound Waves
The diagram above uses the coils of a spring similar to a Slinky toy to represent individual molecules
of a sound conducting medium. The molecules in the medium are influenced by adjacent molecules
in much the same way that the coils of the spring influence one another. The source of the sound in the
is at the left. The compression generated by the sound source as it moves propagates down the length of
the spring as each adjacent coil of the spring pushes against its neighbor. It is important to note that,
although the wave travels from one end of the spring to the other, the individual coils remain in their same
relative positions, being displaced first one way and then the other as the sound wave passes. As a result,
each coil is first part of a compression as it is pushed toward the next coil and then part of a rarefaction as
recedes from the adjacent coil. In much the same way, any point in a sound conducting medium is
subjected to compression and then rarefaction. At a point in the area of a compression, the pressure
in the medium is positive. At a point in the area of a rarefaction, the pressure in the medium is negative.
widely used in ultrasonic cleaning machine and high-power industry cleaning devices.