This method can be very precise in terms of temporal and spatial resolution because the time-of-flight measurement can be derived from tracking the same incident (received) waveform either by reference level or zero crossing.
The diagrams show the sound fields of an unfocused and a focusing ultrasonic transducer in water, plainly at differing energy levels.
Materials with this property change size slightly when exposed to a magnetic field and make practical transducers.
[8] Medical ultrasonic transducers (probes) come in a variety of different shapes and sizes for use in making cross-sectional images of various parts of the body.
The transducer may be used in contact with the skin, as in fetal ultrasound imaging, or inserted into a body opening such as the rectum or vagina.
[10][11] Ultrasonic sensors can detect the movement of targets and measure the distance to them in many automated factories and process plants.
They are being tested for a number of other automotive uses including ultrasonic people detection and assisting in autonomous UAV navigation.
Ultrasonics is a great solution for clear object detection and for liquid level measurement, applications that photoelectrics struggle with because of target translucence.
As well, target color or reflectivity do not affect ultrasonic sensors, which can operate reliably in high-glare environments.
In these devices, ultrasound from the transducer (microphone) is converted down to the human hearing range (Audible Sound = 20 Hz to 20 kHz).
An ultrasonic transducer is affixed to a stainless steel pan which is filled with a solvent (frequently water or isopropanol).
Ultrasonic testing is also widely used in metallurgy and engineering to evaluate corrosion, welds, and material defects using different types of scans.