Applications of Ultrasonic Sensors

　　I believe you can tell from the name that ultrasonic sensors are sensors developed using the principle of ultrasound. They have a particularly strong ability to penetrate liquids and solids, so they are widely used in industry, biological research, and medical research.

　　Ultrasonic waves have many uses in sensors, mainly in:

　　1. Use ultrasonic wave to measure liquid level

　　Ultrasonic level measurement is made by using the reflection characteristics of ultrasonic waves at the interface between two media. If the time interval from the emission of ultrasonic pulses to the transducer receiving the reflected wave is known, the height of the liquid surface can be calculated. According to the functions of the transmitting and receiving transducers, sensors can be divided into single transducers and dual transducers.

　　The ultrasonic transmitting and receiving transducers can be set in the liquid medium to allow the ultrasonic wave to propagate in the liquid medium; the ultrasonic transmitting and receiving transducers can also be installed above the liquid surface to allow the ultrasonic wave to propagate in the air, but the ultrasonic wave is greatly attenuated in the air.

　　2.Use ultrasonic to measure thickness

　　Ultrasonic measurement of the thickness of metal parts, steel pipes and other materials has some advantages, such as high measurement accuracy, light test instruments, easy reading or continuous automatic detection. However, ultrasonic measurement is difficult for materials with large sound attenuation, as well as parts with uneven surfaces or irregular shapes.

　　The pulse echo method is commonly used in ultrasonic thickness measurement. The principle of thickness measurement is that the main controller generates a pulse signal with a certain repetition frequency, sends it to the transmitting circuit, and excites the piezoelectric probe through current amplification to generate repetitive ultrasonic pulses, which are coupled to the workpiece being measured. The pulse propagates to the other side of the workpiece and is reflected back and received by the same probe.

　　3. Use ultrasonic flow measurement

　　There are many types of ultrasonic flow meters, but there are two most commonly used in industry: one is the propagation time difference method, and the other is the Doppler method. Both flow meters are used for liquid measurement.

　　When ultrasonic waves propagate in a fluid, the propagation speed in a static fluid and a flowing fluid is different. This feature can be used to calculate the velocity of the fluid, and then the flow rate of the fluid can be known based on the cross-sectional area of ​​the pipeline fluid.