How to calibrate displacer type level transmitter for an interface level measurement?
Calibration of any transmitter can be done by dry and wet methods. In the dry method, you need to calculate the equivalent input. And simulate it using calculated i/p. And for displacer, you need to calculate the weight.
Wet calibration is more simple you just need to use the process as the IP. Normally use dummy ip.
For interface level, first, you can fill the displacer chamber with lither liquid up to 100%, then the op should show 4mA.
Then drain the first liquid, second fill the chamber with heavy liquid up to 100%. The Op transmitter should show 20mA.