Ultrasonic sensors
An ultrasonic sensor is an electronic device that measures the distance of a target object by emitting ultrasonic sound waves and converts the reflected sound into an electrical signal. Ultrasonic waves travel faster than the speed of audible sound. Ultrasonic sensor systems are based upon interactions between the incident ultrasonic waves and the object to be imaged. For example, the incident waves may be reflected from boundaries; the reflections may be sensed and their data combined to indicate the location of the boundary.
Clearly, the use of ultrasonic sensors is applicable only to processes where a significant interaction occurs, and perhaps where such interactions provide a greater level of measurable signal than that available using other methods of transduction.
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