Design of ultrasonic liquid level sensor for sealed container

In view of problem that existing ultrasonic liquid level detection methods need to open door of container in process of installing, so as to damage the container structure and affect sound wave because of volatile medium, a non-contact ultrasonic liquid level sensor was designed. Selection of ultrasonic frequency of the sensor was analyzed, and hardware circuit implementation scheme of the sensor was also given. According to principle of ultrasonic liquid level detection, the sensor takes AT89S52 as core control chip , uses ultrasonic transducer with transceiver and selects nRF2401 as wireless transceiver module to realize level measurement and data transmission of sealed container. The test results show that the sensor has high precision and relative error is within 3%, which meets needs of real-time measurement of local level.