How can the zero-point shift of liquid level during on-site measurement be adjusted for intelligent differential pressure transmitters?

The HART hand controllers come in 275 and 375 versions; I’ll send you the connection details so you can check the manual! http://bbs.hcbbs.com/viewthread.php?tid=33253 If you don’t have enough funds, participate more often!

Thank you to the person above; what I meant was not how to use HART, but rather how to calibrate an intelligent differential pressure transmitter for level measurement. I’ll edit my post.

It depends on how it is installed; whether it is a positive migration or a negative migration determines the measurement methods, and thus the debugging procedures vary accordingly.

First, thanks to the person who posted above. If there is negative migration, how should it be debugged in detail?

Don’t be in too much of a hurry either. Take a good look at the book on instrument technicians; laying a solid foundation is what really matters. It’s hard to say right now.

First, configure the transmitter by setting parameters such as the range. The transmitter is in a stop mode: the positive and negative pressure taking valves are closed, the vent valve is open, the positive and negative pressure valves of the three-valve assembly are open, the balance valve is closed, and the conduit is filled with isolation fluid or process medium. The differential pressure value sensed by the transmitter is read using a communicator and entered as the lower limit of the measurement range; the upper limit will be adjusted automatically without the need for manual setting. Then store and exit, and the table will be created. What has been done above is negative transfer.

Thank you, the information behind the moon is very detailed. By the way, how do I adjust it for positive migration?

The differential pressure value between 0 and full scale can be calculated, and it can be set using a handheld controller.

If it’s a smart transmitter, it’s not very complicated… there’s no need for calculations or any other settings. Step 1: Measure the height difference between the high-pressure side and the low-pressure side of the differential pressure transmitter; calculate the maximum differential pressure value based on the density of the liquid being measured. Step 2: Enter the calculated differential pressure value into the transmitter. Step 3: Install the differential pressure transmitter (make sure to avoid installing it with the high-pressure and low-pressure sides reversed). If it’s a differential pressure transmitter with a capillary, no special attention is needed; but if it uses pressure conduits, these conduits must be filled with an isolating fluid (or the fluid being measured). Step 4: Ensure that the level of the liquid being measured is at zero; adjust the transmitter’s zero point to this position. That’s all there is to the setup. As long as the range is set correctly and the density remains constant, the smart transmitter will work fine—just adjust the zero point, and the transmitter will automatically handle the negative offset

Determine whether it should be installed above or below position 0, then make adjustments through calculation or actual adjustment

Positive migration is required when the negative pressure side is connected to the atmosphere or the gas phase inside a container, and the positive pressure measurement point is located above the transmitter’s installation site. The method is the same; only the negative pressure side should not be filled with liquid

The answers from everyone upstairs have been very inspiring to me; I feel that the Haichuan Forum is truly a warm place, and I realize there is still so much knowledge I need to learn. Thank you all!