Ultrasound

• Ultrasound are sound waves with frequencies of over 20,000Hz
• Cannot be heard by humans- out of our range
• Ultrasound waves are partially reflected as they pass from one material to another
• We can use data on how long the waves take to reflect in order to measure distances
  

Pre-natal Scanning- Ultrasound waves are "fired" into the mother's womb, and the reflected waves build up an image of the baby inside.

Cleaning Delicate Objects- the tiny vibrations caused by the ultrasound are used to dislodge dirt from an object. The object is placed into a container of cleaning fluid and ultrasounswaves are fired into it. This method means a low risk of damaging the object and thorough clean.

Detecting Cracks- when ultrasound waves are fired at a surface, some of them may be reflected back in a longer time by flaws in the material.