Ultrasound

Introduction

  • Ultrasound is sound with very high frequency 
  • frequency above 20kHz - inaudible
  • high frequency = short wavelength

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Uses of Ultrasound

1. Industrial Cleaning

  • Ultrasound can be used to clean delicate equipment.
  • Short ? = narrow, focused beam.
  • Vibrations remove dirt effectively by “shaking” dirt loose.
  • No need to dismantle the equipment.

2. Industrial Quality Control

  • Ultrasound waves can detect cracks inside metals.
  • When a sound wave travels from one substance to another, some waves are reflected back as echoes.
  • The reflected waves (echoes) are detected by a computer.
  • An echo = a flaw in the metal > a crack has formed.

3. Pre-Natal Scanning

  • X-rays can be used to see inside the body - (unsafe for a baby)
  • Ultrasound can create images and is safer.
  • Passes through new substance (skin, muscle, bone) > waves are reflected as echoes.
  • The reflected waves (echoes) are detected by a computer.
  • These build up a picture from each echo.

4. SONAR

  • Bats produce ultrasound squeaks > pick up the reflections using their big ears.
  • Brain processes the reflected signals into a mental picture of the surroundings.
  • Ships use SONAR to detect items on the seabed.
  • The pattern of the reflections indicates the depth and shapes.

 

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