Closed-field capacitive liquid level sensor

Patent · Wed Dec 31 23:00:00 EST 1997

OSTI ID:871389

Kronberg, James W ^[1]

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1. Aiken, SC

A liquid level sensor based on a closed field circuit comprises a ring oscillator using a symmetrical array of plate units that creates a displacement current. The displacement current varies as a function of the proximity of a liquid to the plate units. The ring oscillator circuit produces an output signal with a frequency inversely proportional to the presence of a liquid. A continuous liquid level sensing device and a two point sensing device are both proposed sensing arrangements. A second set of plates may be located inside of the probe housing relative to the sensing plate units. The second set of plates prevent any interference between the sensing plate units.

• Research Organization: WESTINGHOUSE SAVANNAH RIVER CO
• DOE Contract Number: AC09-89SR18035
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5722290
• OSTI ID: 871389
• Country of Publication: United States
• Language: English

Related Subjects

/73/324/
arrangements
array
based
capacitive
circuit
circuit comprises
circuit produces
closed
closed field
closed-field
comprises
continuous
continuous liquid
creates
current
current varies
device
displacement
displacement current
field
field circuit
frequency
function
housing
inside
interference
inversely
inversely proportional
level
level sensing
level sensor
liquid
liquid level
located
located inside
oscillator
oscillator circuit
output
output signal
plate
plates
presence
prevent
probe
produces
proportional
proposed
proximity
relative
sensing
sensing device
sensor
sensor based
set
signal
symmetrical
symmetrical array
units
varies