Unveiled! How Ultrasonic Level Difference Meters Precisely Control Wastewater Treatment [Dayu Electronics]
Ultrasonic level difference meter is also a type of ultrasonic level meter. Most ultrasonic level difference meters are split-type, consisting of two ultrasonic transducers. The product can measure the liquid level heights of two different tanks separately, or measure the level difference in the same tank, enabling automated control equipment to make judgments.
The typical application of ultrasonic level difference meters is in the control of screen operation at wastewater treatment plants: by installing one probe of the ultrasonic level difference meter before and after the coarse screen and fine screen, the level difference before and after the screen reflects the degree of screen blockage. This data is transmitted to a PLC controller for analysis and calculation. When the level difference exceeds a preset value, the screen operation is controlled to remove debris. Judging by the level difference ensures normal wastewater passage and reasonably reduces equipment wear.
The measurement principle diagram is as follows:
From the installation principle diagram, we can see that the measurement value of Probe 1 must be higher than that of Probe 2 when measuring the liquid level of the tank. The installation heights of the two probes must be the same. The level difference output by the ultrasonic level difference meter transmitter is the liquid level value of Probe 1 minus the liquid level value of Probe 2.
Product application site:
Example installation diagram of the two probes of the ultrasonic level difference meter
The working conditions below the emitting surface of Probe 1 are:
Installation conditions below ultrasonic probe 1
From the photos of the installation site, we can see a ladder on the left side of the tank, and no obstructions on the right side. At the bottom, we can see the shape and size of the screen. Based on communication with on-site installation personnel, the ultrasonic probe is installed relatively close to the inner wall. According to calculations of installation height and ultrasonic emission angle, the ultrasonic probe should be moved 0.5 meters toward the screen to avoid detecting the concrete wall signal at low water levels.
Probe 2 installation position and lower working conditions:
Installation conditions below ultrasonic probe 2
From the figure above, we can see that the installation of Probe 2 is also relatively close to the inner wall. According to the installation height and the emission angle of the ultrasonic signal, it also needs to be moved 0.5 meters toward the screen to avoid detecting the concrete wall when the water level is low.
High water level measurement diagram of level difference meter probe 2
When the water level is relatively high, although the probe is installed close to the inner wall, the measurement data is very stable.
The ultrasonic level difference meter calculates the liquid level difference between the two tanks by measuring the liquid level heights of Tank 1 and Tank 2 probes, and transmits the data to the PLC. It can also provide switch signals to other equipment through relay outputs.