Transmitter range setting issue
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There used to be a float level gauge, but it has now been replaced by a differential pressure transmitter, with pressure transfer pipes connecting the positive and negative pressures. The original range of the float was from -250 mm to +250 mm; the total height remains 500 mm. May I ask how the range should be set for measuring water?
-4.9-0kpa negative pressure pipe water injection
If it is changed to a pressure vessel at normal pressure, there is no need for negative pressure; it is sufficient to install a positive pressure port, or a single flange, though the cost is higher. It depends on the requirements and on me
Now, when the process indicates it’s empty, it’s expected that the liquid level be at zero, and in that case 12mA should be displayed; I’m not sure what this means
Does the process team understand instrumentation? Then let them handle the instruments, haha, just joking. But regarding this manufacturing process you mentioned, I’m not clear about what the actual requirements are
The zero-point shift issue may need to be considered. Remove the pressure ρgh resulting from the height difference between the negative pressure side and the transmitter, and between the positive pressure side and the transmitter.
Connect the flange on the positive pressure side to the lower part, and connect the flange on the negative pressure side to the upper part; setting the range between –4.9 and 0 kPa is sufficient
The range of the transmitter is 0~500 mmH2O water column, which is equivalent to 0~4.9 kPa. (After migration)
1. Range = density of water * g * 500 mm; g ≈ 9.8. This is the range of measurement. 2. Ensure the positive and negative directions are set correctly, fill the isolation fluid properly, and make sure there are no bubbles in the pressure transfer tube. 3. Close the positive and negative check valves, and open the positive and negative vent valves; zeroing can be done once the isolation fluid is at full level. Note that many floats are used for measuring level. This must be taken care of. If the mediation range is different