Servo level devices as tank gauging instruments are used for custody transfer and inventory control applications with NMi- and PTB-approvals and meet the requirements according to OIML R85 and API 3.1B. Proservo is especially suited for high accuracy custody transfer measurement in crude oil, gasoline, diesel, petrochemicals and chemicals.
Servo level measurement: Measuring Principle
A small displacer is accurately positioned in a liquid medium using a servo motor. The displacer is then suspended on a measuring wire which is wound onto a finely grooved drum housing. When the displacer is lowered and touches a liquid, the weight of the displacer is reduced by liquid buoyancy force. As a result, torque in the magnetic coupling changes, which is measured by 5 sets of Hall sensors.