Blind Zone Must Be Considered When Installing Ultrasonic Level Meters

　　Ultrasonic level meter is installed at the top of a container. Under the control of the electronic unit, the probe emits a burst of ultrasonic pulses toward the object being measured. The sound waves are reflected by the object's surface, and part of the reflected echo is received by the probe and converted into an electrical signal. The time from the transmission of the ultrasonic wave to its re-reception is proportional to the distance from the probe to the object being measured.

　　When installing an ultrasonic level meter, the blind zone issue must be considered. Once the liquid level enters the blind zone, the ultrasonic transmitter can no longer measure the level. Therefore, when determining the range of the ultrasonic level meter, a margin of 50 cm must be reserved.

　　The electronic unit detects this time and calculates the measured distance based on the known speed of sound. The level value is then obtained through subtraction. Since temperature affects the speed of sound, the instrument should measure temperature to correct the sound speed.