If the vessel filled with heavier density fluid so an interface level transmitter should show

Field Instrumentation
1

Interface level transmitter output is

A: Zero

B : 50%

C : 100%

2

Interface level transmitter output is

LRV = 4 mA when tank is fully filled with lighter fluid

URV = 20 mA when tank is fully filled with heavier fluid

4mA (0%) when tank is fully filled with lighter fluid and 20mA (100%) when tank is fully filled with heavier fluid and at 50% interface means 50% heavier fluid and 50% lighter fluid