Level Transmitters – Level Measurement in Pressurized Vessels Closed tanks are not vented → gas phase exists above liquid. 🔹 Gas pressure can be above or below atmospheric. 🔹 If not compensated → level transmitter output will give wrong readings. ✓ Problem: 🔹 Fluctuating gas pressure changes transmitter output → measurement error. 🔹 Gas pressure may be so high → liquid column pressure becomes negligible. ✓ Solution: Differential Pressure (DP) Measurement 🔹 High side → bottom of vessel (liqu