What are the common problems of ultrasonic level meter?
On-site containers are often equipped with stirrers, so the fluctuation of liquid is relatively large, which affects the measurement of ultrasonic level meter. In this case, the rotating speed of the stirrer should be appropriately reduced or the probe should be deviated from the stirring center. The installation of static pipe can also effectively eliminate the influence of stirring on liquid level measurement.
In the process of measuring liquid level with ultrasonic level meter, there is often foam interference. Foams can be divided into dry, wet, neutral and heavy according to their properties.
Dry foam and wet foam can reflect ultrasonic waves back, so they have no influence on ultrasonic level meter measurement. Neutral foam will absorb and diffuse part of ultrasonic waves, which will weaken the reflection of ultrasonic waves and lead to unstable echoes. Therefore, when the medium surface is thick foam, the measurement error of the ultrasonic level meter will be larger or even unable to measure.
When the working environment temperature is very high, the liquid medium is easy to produce steam or fog. As steam is lighter than air, it floats up to the top of the tank, forming a steam layer which can absorb and scatter ultrasonic pulses. The influence of steam layer on measurement can be reduced or weakened by installing static pipe.
Like human eyes, ultrasonic level meters have blind spots. When the object is very close to the eyes, we cannot see clearly. This distance is called blind zone.
The blind zone of ultrasonic level meter varies according to the range. Small range leads to small blind area, while large range leads to large blind area. Therefore, it is required that the highest liquid level to be measured should not be higher than the blind area of ultrasonic level meter.
First of all, the speed of sound cannot propagate under vacuum. The essence of ultrasonic wave is a kind of sound wave, which belongs to mechanical wave, so it cannot propagate in vacuum either.
Secondly, temperature also affects the ultrasonic level meter. Although there is a large pressure value in the parameter summary of ultrasonic level meter, with the increase of temperature, the large pressure value will decrease accordingly. So we should pay attention to parameter when selecting type.
In addition, for the level meter installed outdoors, measures such as adding sunshade can be adopted to reduce the influence of temperature factors.