Sound waves with frequencies higher than the upper audible limit of human hearing are known as ultrasound. The limit varies from person to person however it is approximately 20,000 Hertz. The physical properties of ultrasound are similar to the normal audible sound.
This type of scientific idea is used in many different fields like navigation, medicine, imaging, cleaning, mixing, communication, testing etc. Even in nature, bats and porpoises use this explicit technique for the location of prey and obstacles.
In objects with parts that have some difficulty to reach, for example, spiral tubes and electronic parts, the method of ultrasonic cleaning is employed. Here, the object is dipped in a solution of suitable cleaning material and ultrasonic waves are passed into it. As a result of this, high frequency waves are generated which cause the dirt and grease to detach from the surface.
Detection of Cracks
Ultrasound is used to sight cracks in the metallic components that are utilized in the development of high rise structures like buildings and bridges. They generate and display an ultrasonic waveform that's interpreted by a trained operator, usually with the help of analysis software, to find and categorize flaws in test pieces. High-frequency sound waves reflect from flaws in predictable ways, producing distinctive echo patterns that can be displayed and recorded by movable instruments. A trained operator identifies specific echo patterns corresponding to the echo response from good parts and from representative flaws. The echo pattern from a test piece may then be compared to the patterns from these calibration standards to work out its condition.
SONAR, Sound Navigation, and Ranging is a technique in which sound waves are used to navigate, detect and communicate under the surface of the water.
Medical ultrasound is a diagnostic imaging technique based on it. It's used for the imaging of internal body structures like muscles, joints and internal organs. Ultrasonic images are referred as sonograms. During this method, pulses of ultrasound are sent to the tissue using a probe. The sound echoes off the tissue, wherever different tissues reflect sound varying in degrees. These echoes are recorded and displayed an image.
PRODUCTION OF SOUND WAVE :
These are produced by electronic oscillator using high frequency vibrations of quartz crystal.
PROPERTIES OF SOUND WAVE :
Sound wave of all frequencies carry energy with them, with increase in frequency, vibration becomes faster and also energy contents and force increase. When ultrasound travels in solid, liquid and gas it subjects the particles of matter to face large force and energy.