Ultrasonic sensors are used in different aspects of production practice, and medical applications are one of their most important applications. The application of ultrasound in medicine is mainly to diagnose diseases, and it has become an indispensable diagnostic method in clinical medicine. The advantages of ultrasonic diagnosis are: no pain, no damage to the subject, simple method, clear imaging, high diagnostic accuracy, etc., and thus welcomed by medical workers and patients. Ultrasonic diagnosis is the reflection principle of ultrasonic waves. When ultrasonic waves propagate in human tissue and encounter two layers of media interfaces with different acoustic impedances, reflection echoes are generated at the interface. Each time a reflective surface is encountered, the echo is displayed on the oscilloscope's screen, and the impedance difference between the two interfaces also determines the amplitude of the echo.
In industry, the typical applications of ultrasonic waves are non-destructive testing of metals, ultrasonic thickness measurement and measurement of liquid levels. In the past, many technologies were hindered by the inability to detect the inside of objects, and the emergence of ultrasonic sensors changed this situation. Ultrasonic detection can detect defects on the surface of the material as well as defects within a few meters of the material. Of course, more ultrasonic sensors are fixedly mounted on different devices to "snap" the signals that people need.
The basic principle of ultrasonic measurement of liquid level is that the ultrasonic pulse signal emitted by the ultrasonic probe propagates in the gas, is reflected after encountering the interface between air and liquid, and is calculated after receiving the echo signal and calculating the propagation time of the ultrasonic round-trip. Distance or level height. Ultrasonic measurement methods have many advantages that are unmatched by other methods:
(1) It does not have any mechanical transmission parts and does not touch the liquid to be tested. It is a non-contact type measurement, and is not afraid of electromagnetic interference, strong corrosive liquid such as acid and alkali, etc., so it has stable performance, high reliability and long service life;