Gima UTC2, Instruction Manual

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MA531_EN EN 8
UTC2
ULTRASOUNDS
Physical Elements
Ultrasonic waves are sound waves having frequency higher than to that perceivable from the human ear. The perceivable
frequencies from the man are those between 16 and 20.000 Hz. The frequencies under 16Hz are denominated infra-
sound, while those superior to 20kHz are being denominated ultrasounds.
As all the sonorous waves, ultrasounds require a solid, liquid or gaseous solid material to propagate. The propagation
happens when some of the particles of the mean due to a perturbation start to oscillate and solicit the near particles,
because of the molecular interactions. This provokes compressions and decompressions that propagate each other
through the same mean. The sonorous waves are longitudinal, since the direction of the oscillations of the molecules of
the mean is parallel to the direction of propagation of the wave.
Speed
The speed of propagation of a sonorous wave depends by elastic characteristics of the mean of transmission. For this
reason, it is greater in the solid than in the liquids and it is greater in these last in comparison to the gases.
Medium
Speed(m/sec)
Water 1430
Aluminum 6400
Air 330
Fat 1450
Bone 4080
Blood 1570
Soft tissue 1540
Wavelength
The length of wave is the briefest distance between any two points in which the particles oscillate in phase.
Frequency
The move of a particle from a position and his/her return in the position of departure is defined as cycle. For frequency of
a wave is the number of cycles in the unity of time. The unity of measure of the frequency is the Hertz (Hz).
Amplitude
The amplitude of a wave is the maximum value of the oscillation.
Power
The power is the energy transmitted by a wave in the unity of time.
Intensity
The intensity of a sonorous wave is the energy that crosses the unitary surface in the unitary time.
The unity of measure that one uses is W/cm
2
.
Duty cycle (cycle of service) or modulation