Can anybody send or tell me the best way of calculation and calibration of displacer type interface level transmitter.
If you want to calibrate a displacer type interface level measuring instrument at field the procedures are simple.
Step-1: Fill up the displacer chamber up to the measurement range (up to the upper nozzle)with lower density fluid and now adjust the transmitter zero to 4 mA.
Step-2: Now fill up the displacer chamber with higher density of fluid and adjust the transmitter span to 20 mA.
That's all! This finishes your calibration. If you don't want to calibrate the transmitter in situ, then you have to take it to the lab and use calculated weight to calibrate the transmitter.
Weight to be calculated considering:
1. When displacer is fully submerged in upper(lower density) fluid and that will give you weight for 4 mA transmitter output;
2. When displacer is fully submerged in lower fluid (higher density fluid)and that will give you weight for 20 mA transmitter output.
Hope this will be of some help to you.