Capacitance-type material level indicator

Measuring and testing – Liquid level or depth gauge – Immersible electrode type

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Details

324 61R, G01F 2326, G01R 2726

Patent

active

046241396

ABSTRACT:
A system for indicating level of material in a vessel as a function of material capacitance comprising a bridge circuit which includes a capacitance probe adapted to be disposed in a vessel so as to be responsive to variations in capacitance as a function of material level. An adjacent bridge arm includes a plurality of capacitors coupled to controlled electronic switches for selective connection into the bridge circuit. The bridge circuit is powered by an rf oscillator, and a differential amplifier is connected across the bridge circuit for detecting the balance condition of the bridge. An automatic calibration circuit includes a digital counter having outputs connected to the electronic switches. A comparator is responsive to the differential amplifier for enabling operation of the counter during a calibration mode of operation for selectively connecting the fixed capacitors into the bridge circuit until a preselected balance condition, corresponding to a preselected reference material level, is obtained. Thereafter, the differential amplifier is responsive to variation of probe capacitance from the reference level to indicate material level.

REFERENCES:
patent: 2357023 (1944-08-01), Reid et al.
patent: 2919401 (1959-12-01), Cole et al.
patent: 3339412 (1967-09-01), Maltby
patent: 3534606 (1970-10-01), Stamler et al.
patent: 3879644 (1975-04-01), Maltby
patent: 3934197 (1976-01-01), Pettersen et al.
patent: 4039939 (1977-08-01), Wagner
patent: 4063447 (1977-12-01), Mathison
patent: 4107658 (1978-08-01), Hill et al.
patent: 4208625 (1980-06-01), Piso
patent: 4448072 (1984-05-01), Tward
patent: 4499766 (1985-02-01), Fathauer et al.

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