Measuring levels in liq. storage tanks - using relief tube and optical conductors with sensors to derive hydrostatic pressure while eliminating barometric pressure fluctuations

摘要

The arrangement measures the hydrostatic pressure height of the liq. column w.r.t. the barometric pressure at a point below the level of liq. using optical conductors with pressure sensors. The measurement valves are not affected by barometric pressure fluctuations. The end of the optical conductor facing the container has a pressure sensitive transducer sealed against the liq. The sensor has an open tube connecting it to barometric pressure at its internal chamber pref. to the rear side of the membrane. The tube connecting the chamber to barometric pressure is fed out of the container via the optical conductor. The optical conductor may itself serve as the connecting tube.