16-03-2012, 12:06 PM
ULTRASONIC SOUND WAVES –ITS APPLICATIONS IN SCIENCE
Ultrasonics.ppt (Size: 1.49 MB / Downloads: 140)
Ultrasonics is used in day to day life in many fields:
cleaning metal parts of instruments, medical equipments.
Flaw detection in Metallurgy, Railways, Iron ropes etc.,
In Scientific research .
In Medical field as sonogram of human body.
What is ultrasonics?
Ultrasound is the sound wave
with a frequency above the audible range of human hearing
i.e, : above 20 KHz
up to 5 MHz or more
Dolphins are famous for their sonar, so that they can make acoustic mental "images" of the environment.
This way they can detect in murky waters fish shoals located hundreds of meters away.
The sonar employs sounds from 250 Hz to 220 kHz.
Development in the field ultrasonics
After the First World War , rapid development took place in the field of electronics.
In 1934 , Skolov in the USSR published the first known work on ultrasonic flaw detection.
The use of pulse methods derived from RADAR techniques enhanced the ultrasonics considerably.
In the post war years it became widely used in the non destructive testing of materials,
in medical diagnosis and
in various forms of instrumentation and control.