Capacitive fluid level sensor
Patent 5103368 Issued on April 7, 1992. Estimated Expiration Date: 
May 7, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
May 7, 2010. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2700901 2950426 2998559 3192455 3827300 Capacitive means for measuring the level of a liquid Capacitive scheme for measuring the level of a liquid Liquid level and quantity measuring apparatus Dielectric liquid level sensor and method Electrostatic capacitor type sensing device Patent #: 4943889 InventorApplicationNo. 519731 filed on 05/07/1990US Classes:361/284, Liquid level73/304CCapacitativeExaminersPrimary: Griffin, Ronald W.Attorney, Agent or FirmInternational ClassG01F 023/26AbstractA device that determines liquid level or volume by means of charging a plurality of capacitors in sequence. Each capacitor is charged for a fixed time interval. The voltage level obtained is a function of the liquid level and is compared with a known voltage to obtain an output signal that can be used to represent liquid depth. The capacitors are formed by two concentric tubes, one inside the other in a spaced relationship. The tubes reduce the effect of sloshing in the tank, resulting in a more stable reading. To measure volume or level in an irregular shaped tank, the capacitors can be arranged in a non-linear manner. The device has no moving parts to wear out and thus results in higher reliability and longer life. | |
