Question - Do you know the working of a level troll ?
Answer -
The variation in buoyancy level resulting from a fluid level change varies the displacer’s net weight to increase or decrease the torque armload. This change is directly proportional to fluid level change and real gravity.
The subsequent torque tube movement shifts the rotor angular motion in RVDT resulting in a rotor shift proportional to the displacement of the rotor, which is transformed and amplified to a D.C. Up-to-date.