The ultrasonic level gauge is also called the ultrasonic level gauge, the ultrasonic level gauge and the ultrasonic level gauge. It is a common non-contact liquid level instrument. Suitable for petroleum, chemical industry, tap water, sewage treatment, water conservancy and hydrology, iron and steel, coal mine, electric power, transportation and food processing industries. It is easy to install and operate, wide applicability and low price. So, what are the advantages of the ultrasonic level gauge, what are the skills when installing it, and what problems should we pay attention to? Xiaobian helps you sort it out as follows:
Installation of ultrasonic level gauge
I. Advantages and disadvantages of ultrasonic level gauge
The ultrasonic level gauge has the advantages of convenient installation, stable performance, high measurement accuracy and low price. But it is sensitive to temperature, dust, steam and pressure.
2. Clarify the Principle and Find the Position
Principle of ultrasonic level gauge: The ultrasonic level gauge is installed on the upper part of the container. Under the control of the electronic unit, the probe emits a bunch of ultrasonic pulses to the measured object. Acoustic waves are reflected by the surface of the object, and part of the reflected echoes are received by the probe and converted into electrical signals. The time from the transmission of the ultrasonic wave to the re-reception is proportional to the distance from the probe to the object under test. The electronic unit detects the time and calculates the measured distance according to the known sound velocity. The distance from the probe to the bottom of the tank - the distance from the probe to the liquid level = the actual liquid level or the material level height. Therefore, the ultrasonic level gauge should be installed on the top of the container, aiming at the liquid surface to be measured.
III. Installation Notices for Site Use Time
1. Vertical mounting probe
When the transducer is installed, the transmitting surface of the transducer should be parallel to the liquid surface to be detected, so that the sound wave can be emitted vertically to the surface of the object under test. This ensures maximum energy return.
Installation Skills: If there is steam in the field environment, it is easy to form water droplets attached to the surface of the probe, and the range of the probe is much larger than the actual distance to be measured. Then it can be tilted about 3 degrees, so as to avoid the influence of water droplets.
2. Avoiding Blind Areas
The distance from the highest liquid level to the probe surface of the ultrasonic liquid level meter should be greater than the blind area of the probe.
It should be noted here that our blind area is measured in a relatively ideal state. Therefore, if we install a closed tank, then the blind zone value should be increased by 20%. If the liquid is agitated and a long tube is used to install it, then the blind area value should be increased by 20%. In order to avoid the blind area, we often use lengthened catheter to avoid the blind area. When installing the lengthened catheter, the sharp angle of the probe must be ensured.
3. Away from tank walls and obstacles
If the tank wall is smooth and the liquid level decreases, there will be no hanging material, then most of the distance from the wall 30 cm can be installed. If the grouting wall is rough, the probe should be installed away from the tank wall. The bottom of the tank is not flat, so errors may occur at zero liquid level. If it is a conical bottom, you can consider installing the probe directly above the top of the cone. For the circular bar, as long as the distance exceeds 1 m and the diameter does not exceed 5 cm, the effect is not significant. Otherwise try to avoid it. But for the horizontal bar and the tank wall with right angle, we should avoid it as far as possible.
On-site ultrasonic level gauge
4. Avoid stirring and fluctuation
If agitation or fluctuation occurs, lengthened conduits can be used for installation. The catheter is directly applied to the bottom of the liquid level. The diameter of the catheter is only larger than the radiation surface of the probe, but the inner wall of the catheter should be smooth, and no material is hung during the rising and falling of the liquid level. The liquid in the tube is identical with that outside the tube. If a large range is not suitable for catheter installation, the range can be reduced, depending on the size of the wave.