Gauge for measuring the level or the conductance of a liquid present between two electrodes
First Claim
1. In a vessel holding a liquid a gauge for measuring the height of the liquid in the vessel comprising a measuring electrode (M) and a compensation electrode (R) in the vessel, and a circuit which measures the capacitance CM of the measuring electrode and the capacitance CR of the compensation electrode, each with respect to a wall of the vessel as counter-electrode, using the liquid in the vessel as dielectric, whereby the quotient CM /CR varies with the height of the liquid in the vessel, characterized in that the measuring electrode and the compensation electrode are parallel and of the same length, but differ in surface area and shape to such extent that said quotient varies as a linear function of the height of the liquid in the vessel.
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Accused Products
Abstract
A gauge for measuring the height of a liquid in a vessel comprises a measuring electrode (M) and a compensation electrode (R) in the vessel, and a circuit which measures the capacitance CM of the measuring electrode and the capacitance CR of the compensation electrode, each with respect to a wall of the vessel as counter-electrode, using the liquid in the vessel as dielectric. The quotient CM /CR varies with the height of the liquid in the vessel. The measuring electrode and the compensation electrode are parallel and of the same length, but differ in surface area and shape to such extent that such quotient varies as a linear function of the height of the liquid in the vessel.
43 Citations
9 Claims
- 1. In a vessel holding a liquid a gauge for measuring the height of the liquid in the vessel comprising a measuring electrode (M) and a compensation electrode (R) in the vessel, and a circuit which measures the capacitance CM of the measuring electrode and the capacitance CR of the compensation electrode, each with respect to a wall of the vessel as counter-electrode, using the liquid in the vessel as dielectric, whereby the quotient CM /CR varies with the height of the liquid in the vessel, characterized in that the measuring electrode and the compensation electrode are parallel and of the same length, but differ in surface area and shape to such extent that said quotient varies as a linear function of the height of the liquid in the vessel.
- 7. In a vessel holding a liquid a gauge for measuring the height of the liquid in the vessel comprising a measuring tube, a measuring electrode (M) and a compensation electrode (R) in the vessel, and a circuit which measures the capacitance CM of the measuring electrode and the capacitance CR of the compensation electrode, each with respect to a wall portion of the measuring tube as counter-electrode, using the liquid in the vessel as dielectric, characterized in that the measuring electrode and the compensation electrode are parallel and of the same length, the measuring electrode is arranged opposite to said wall portion of the measuring tube, and the horizontal distance between the measuring electrode and said wall portion varies with the height at which such distance is measured, while the distance between the compensation electrode and the measuring tube is constant, whereby the quotient CM /CR varies as a linear function of the height of the liquid in the vessel.
Specification