Why DP transmitter is used for close tank level measurement

Explain why do we use differential pressure transmitter for close tank level measurement

By using a DP transmitter you can measure two kinds of pressure, liquid, and air and with the difference of that, you will get the correct level of liquid in a closed tank.

To get actual level and equalized HP and LP pressure

We can also take elevation and suppression with an impulse line. you will get the actual level of the tank through DP transmitter.