Ultrasonic level gauge working blind area

The working principle of the ultrasonic level gauge is based on the transmission and reception of ultrasonic waves. The speed of ultrasonic transmission in the air is constant, the ultrasonic waves are emitted, and then the waves reflected by the liquid surface or the object surface are received, and the time is counted from the start of the transmission until the end of the echo is received. Ultrasonic transmission time in the air will be set. Because it is a round trip, the actual distance is half the distance. The depth of the tank or the height of the tank is certain. The actual liquid level is the depth of the pool minus the distance measured by the ultrasonic level gauge, which is the height of the liquid level or level. As a result, ultrasound is used to measure the liquid level or level.

The blind area of ​​the ultrasonic liquid level gauge is different depending on the measuring range. With a small range, the blind area is small and the range is large, so the blind area is large. But generally between 30cm-50cm. Therefore, the blind area must be taken into consideration when installing ultrasonic level gauges. In special occasions, the blind area will be required to be small. At this time, the ultrasonic liquid level gauge in the small blind area may be considered. The blind area is generally only 4-6 cm. But its range is also relatively small, only 0.6m. In many areas of liquid level measurement, due to space limitations and restrictions on installation conditions, ultrasonic level gauges with small dead zones are required.

The liquid level of the ultrasonic level gauge enters the blind area and usually shows the corresponding liquid level position of the secondary echo. For example, if the dead zone is 0.3m and the distance from the liquid surface to the surface of the transducer (or probe) is 0.2m, the level gauge will display the corresponding liquid level value with a distance of 0.4m. As the liquid level is measured when the liquid level is measured, the sound pulse emitted by the ultrasonic level gauge is reflected by the liquid surface. After the echo reaches the surface of the transducer (or probe), it will be reflected back to the liquid surface again. It is reflected back to the transducer and received again. The echo at this time is the secondary echo. If the reflection conditions are good, you may also receive multiple echoes (echoes that return multiple times).