Electrodesalination Rosemount double-flange level issue
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The distance between the two flanges is 1 meter. The transmitter is fine; the pressure difference between positive and negative pressures relative to atmospheric pressure is -8.4 kPa, and the zero point is -3.4. Thus, the measurement range is from -8.4 to -3.4. However, after connecting the flanges, the measured value corresponded to only 40% of the actual level. Later, the measurement range was changed to -1 to 4, and then the measured value matched the actual level. But even when it was 20% below the actual level, the transmitter still showed 40% without any change. Each time the measurement range was adjusted, it managed to match the actual level, yet the value read by the transmitter did not change along with the actual level. Could you please tell me what the reason for this is?
Is a double-flange transmitter being used to measure the liquid level? What is a medium? Is the flange diaphragm a convex diaphragm or a flat diaphragm? For double flanges, the two flanges of the transmitter should first be adjusted to the flange alignment position without being connected. Check the value displayed in the actual table header, and then perform the corresponding migration. Based on what you’ve described, check whether there is crystallization in the medium or any other issues
The client needs to clarify all the operating conditions, such as temperature and the medium being measured, in order for it to be possible to determine the cause
The medium is crude oil and water at 130 degrees, and the flange diaphragm is a flat diaphragm
Original poster, please give me an email address so I can send you some materials for you to check if they work
The zero point range of the double flanges used for measuring the boundary as described by the poster has been set incorrectly; the zero point should be set under conditions of pure oil, while the range should be set under conditions of pure water, rather than based on the pressure difference when positive and negative pressures are exposed to the atmosphere. As you mentioned, the differential pressure value in this case is very low; the range is quite small. If the density of crude oil is taken as 0.8, the pressure would be around 2 Kpa, making it difficult to measure
463737763@qq.com Thank you very much
Level measurement is different from height measurement. What the original poster is referring to is the method of level measurement; in height measurement, the differential pressure is zero when there is only light medium present, and it represents the full scale value when there is only heavy medium present.
Learn * one more time… Thank you, jiaoyachong6@163.com
Learn*learn*: Dual-flange level transmitters and liquid level sensors are not the same thing