The term ultrasonics is said to be the vibrations of frequencies which is greater than the upper limit of the audible range for humans that is greater than about 20 kilohertz. The term sonic is said to be applied to waves that are ultrasound of very high amplitudes. The hypersound which is sometimes known as praeter sound or the microsound is the waves of sound of frequencies that is greater than 1013 hertz.
At such a high level of frequencies, i.e a frequency of about 1.25 × 1013 hertz, it is very difficult for a wave of sound to propagate efficiently. It is impossible for the longitudinal waves to propagate at all even in a liquid or a solid. That is because the molecules of the material in which the waves are traveling that cannot pass the vibration along rapidly enough.
Ultrasonic Machine
Ultrasound is the wave of sound with frequencies that is higher than the upper audible limit of human hearing. The ultrasound is not different from "normal" that is the audible sound in its physical properties. Except that humans cannot hear it. This limit is said to vary from person to person and is approximately 20 kilohertz that is written as 20,000 hertz in healthy young adults. The devices that are the ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.
Ones is used in many different fields. The term that is ultrasonic devices that are used to detect objects and measure distances. By imagining the ultrasound or sonography is often used in medicine. In the nondestructive testing which is of structures and products. The ultrasound is said to be used in detecting invisible flaws.
Industrially the term that is ultrasound is used for cleaning, and mixing, and accelerating processes that are chemical. Animals such as bats generally use ultrasound voice for locating prey and obstacles as well.
The term that is acoustics which is the science of sound starts as far back as Pythagoras in the 6th century BC who wrote on the properties which are the mathematical properties of stringed instruments. In 1794 echolocation which are in bats was discovered by Lazzaro Spallanzani when he demonstrated that bats hunted and navigated by inaudible sound. In 1893 Francis Galton invented the Galton whistle that is an adjustable whistle that produced ultrasound which he used to measure the hearing range of humans and other animals as well. This was demonstrating that many animals could hear sounds above the hearing range of humans. In 1917 the first application of the technology of ultrasound was an attempt to detect submarines by Paul Langevin. The effect, which is known as piezoelectric, was generally discovered by Jacques and Pierre Curie in 1880 which was useful in transducers to generate and detect ultrasonic waves in air and water.
Ultrasonic Frequency
The term that is sounds with a frequency of 20 kHz and higher are said to be referred to as ultrasound or we can say ultrasonic sound. We can say that the high frequency sound is sound of which the frequency lies between 8 and 20 kHz. The sound which is the high frequency sound with a frequency over 16 kHz can hardly be heard but it is not completely inaudible. The sound which is the high frequency sound and even ultrasound in the lower frequency zone that is up to 24 kHz can be audible if the sound level is high enough. The sound that threshold is the level of the sound where sound can be perceived that usually rises sharply once the frequency and therefore the tone) becomes higher. A person who is younger hears high frequency sound better and their hearing range is greater toward the high frequencies.
The term that is ultrasound and sound of the frequencies that are of high range are widely applied in the industry and health care and also in movement detectors, the range finders and remote controls as well. We can notice that typical for these applications is that their sound levels are low and that the sound frequency usually lies below 100 kHz. The applications that are the medical and industrial generally make use of a wider range of ultrasound frequencies which is up to MHz and usually use much higher sound levels.
Ultrasonic Vibration
The wavelength or the vibrations that are beyond the audible limit of the ear of the humans are called ultrasonic or supersonic vibrations.
These vibrations have very possibilities that are interesting in the field of investigative dermatology. The purpose that is of my brief preliminary report is to call this subject to the attention of dermatologists which is as there are few reports that are on it in our literature.
The frequencies which are most commonly used in various biological, and medical, and commercial, and military applications have ranged from 100 to 1500 kilocycles.
The waves that are the ultrasonic waves generally differ from electromagnetic ones in that they do not traverse a vacuum.
The term Ultrasonics is a name which is given to various specific topics in which the properties of ultrasound are exploited. The ultrasound is simply sound whose frequency is too high to be heard by the ear of human beings, that is to say the frequency is above c 20 kHz.
FAQs on Ultrasonics
1. What are ultrasonics?
Ultrasonics, or ultrasound, refers to sound waves with frequencies higher than the upper limit of human hearing. While humans can typically hear sound frequencies between 20 Hz and 20,000 Hz (or 20 kHz), ultrasonic waves have frequencies above 20 kHz. These waves are not audible to us but carry significant energy and have unique properties used in various technologies.
2. What is the difference between ultrasonic, infrasonic, and audible sound?
The primary difference lies in their frequency ranges, which determines whether they are audible to humans. The three categories are:
- Infrasonic Sound: Frequencies below 20 Hz. Humans cannot hear them, but some animals, like elephants and whales, can use them for communication.
- Audible Sound: Frequencies between 20 Hz and 20 kHz. This is the normal range of human hearing.
- Ultrasonic Sound: Frequencies above 20 kHz. This is beyond human hearing but is used by animals like bats and dolphins and in technologies like medical sonography and SONAR.
3. What are the main properties of ultrasonic waves?
Ultrasonic waves have several distinct properties that make them useful for specific applications:
- High Frequency and Short Wavelength: This allows them to travel in well-defined, narrow beams with minimal diffraction, which is crucial for imaging.
- High Energy: Despite being inaudible, they carry a high amount of energy that can be used for cleaning, welding, or medical procedures.
- Good Directionality: They can be directed in a straight line, making them ideal for detecting objects and measuring distances accurately.
- Reflection and Scattering: They reflect off different materials and tissues in predictable ways, forming the basis of ultrasound imaging and non-destructive testing.
4. How are ultrasonic waves typically produced for industrial and medical use?
Ultrasonic waves are most commonly generated using the piezoelectric effect. This process involves a specific type of crystal, such as quartz. When a high-frequency alternating electric voltage is applied across these crystals, they rapidly expand and contract. This mechanical vibration of the crystal surface pushes and pulls the surrounding medium (like air or water), creating high-frequency sound waves, i.e., ultrasound.
5. What are some important applications of ultrasonics in technology and medicine?
The unique properties of ultrasonics make them vital in many fields. Key applications include:
- Medical Imaging (Sonography): To create images of internal organs, monitor foetal development, and diagnose conditions without using ionising radiation.
- SONAR Systems: Used in ships and submarines for Sound Navigation and Ranging to map the seabed and detect underwater objects.
- Industrial Cleaning: High-energy waves create tiny bubbles in a liquid to scrub delicate or complex parts, like jewellery and electronic components.
- Non-Destructive Testing (NDT): To detect internal flaws, cracks, or defects in metal structures and pipelines without causing damage.
- Ultrasonic Welding: To join plastics and dissimilar materials using high-frequency vibrations.
6. How does SONAR work using the principle of ultrasonics?
SONAR (Sound Navigation and Ranging) uses ultrasonics to measure distances underwater. A transmitter on a ship sends a powerful ultrasonic pulse down into the water. This pulse travels until it hits an object, like the seabed or a submarine, and reflects back as an echo. A receiver on the ship detects this echo. By measuring the total time (t) it takes for the pulse to travel to the object and return, and knowing the speed of sound in water (v), the distance (d) to the object can be calculated using the formula: 2d = v × t.
7. Why are high-frequency ultrasonic waves preferred for medical imaging (sonography)?
High-frequency ultrasonic waves are preferred for medical imaging because of the direct relationship between frequency and image resolution. A higher frequency corresponds to a shorter wavelength. Shorter wavelengths can detect and resolve much smaller details within the body. This allows sonographers to create clear, detailed images of organs, tissues, and blood vessels. While lower frequencies penetrate deeper into the body, they provide less detailed images, so a balance is chosen based on the organ being examined.
8. How do animals like bats and dolphins use ultrasonics?
Bats, dolphins, and some other animals use ultrasonics for a biological process called echolocation. They emit high-frequency sound pulses and listen for the echoes that bounce back from objects in their environment. By interpreting the time delay and direction of these echoes, they can:
- Navigate in complete darkness (in the case of bats).
- Locate and track prey.
- Identify the size, shape, and texture of objects around them.
This natural sonar system is highly sophisticated and allows them to 'see' their surroundings using sound.
