Floatless fluid level gauge

Claim 2

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two conductive sheets non-conductively joined along an edge of each to form a unitary sheet and said third electrode is a conductive sheet disposed in spaced relatioNship to said pair of electrodes.

Claim 3

The gauge of claim 1 wherein said conductive sheets are planar in form.

Claim 4

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two congruent right triangular conductive sheets non-conductively joined along their hypotenuses to form a rectangular sheet and said third electrode is a rectangular conductive sheet disposed in spaced relationship to said pair of electrodes.

Claim 5

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two congruent right triangular conductive sheets non-conductively joined along their hypotenuses to form a rectangular sheet and said third electrode is a rectangular conductive sheet disposed in spaced relationship to said pair of electrodes.

Claim 6

The gauge of claim 3 wherein said third electrode is disposed in a plane parallel to the plane of the first mentioned rectangular sheet.

Claim 7

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two conductive tubes of similar cross-section disposed one above the other and said third electrode is an elongated conductive body disposed within said tubes.

Claim 8

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two conductive tubes of similar cross-section disposed one above the other and said third electrode is an elongated conductive body disposed within said tubes.

Claim 9

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two right cylindrical segments having similar cross-sections and disposed coaxially one above the other, and said third electrode is disposed within said right cylindrical segments parallel to the axis thereof and generally coextensive therewith.

Claim 10

A floatless fluid level gauge for gauging fluid comprising: a pair of electrodes comprising first and second electrodes immersed in said fluid; means for maintaining a potential difference between said first and second electrodes; a third electrode immersed in said fluid and disposed in the current path between said first and second electrodes, said first, second and third electrodes being so configured that the ratio of the resistance through said current path in said fluid between said first and third electrodes with respect to the resistance through said current path in said fluid between said second and third electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; and means for sensing the potential of said third electrode, wherein said pair of electrodes comprise two right cylindrical segments having similar cross-sections and disposed coaxially one above the other, and said third electrode is disposed within said right cylindrical segments parallel to the axis thereof and generally coextensive therewith.

Claim 11

The gauge of claim 6 wherein said right cylindrical segments are of equal height.

Claim 12

The gauge of claim 6 wherein said third electrode is a third right cylindrical segment disposed within said two right cylindrical segments.

Claim 13

The gauge of claim 6 wherein one of said two cylindrical segments is threaded over a portion of its outer surface, and with additionally, a base member closing one end of said one segment.

Claim 14

The gauge of claim 9 wherein said base member is shaped for engagement by a wrench.

Claim 15

The gauge of claim 9 wherein said base member has a hollowed portion therein and wherein saiD gauge additionally includes means for sensing the potential of said third electrode comprising an integrated circuit device disposed within said hollowed portion of said base member.

Claim 16

The gauge of claim 9, with additionally, fibrous filter means for damping the movement of fluid within said gauge.

Claim 17

The gauge of claim 9 wherein said means for sensing comprises voltmeter means responsive to the potential appearing on said third electrode.

Claim 18

The gauge of claim 9 wherein said means for sensing potential comprises: potential responsive switching means connected to said third electrode; and, indicator means controlled by said switching means.

Claim 19

A floatless fluid level gauge comprising: three electrodes immersed in the fluid to be gauged, said electrodes being so configured that the ratio of the volume of said fluid between a first and third of said electrodes with respect to the volume of said fluid between said third and a second of said electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; means for maintaining a potential difference between two of said electrodes, whereby an electric current is caused to flow between said two electrodes, the other of said electrodes being disposed in the current path between said two electrodes; and, means for sensing the potential of said third electrode, wherein said first and second electrodes comprise two right cylindrical segments of unequal cross-section disposed coaxially one within the other, and said third electrode is a right cylindrical segment of cross-section intermediate to the cross-sections of the electrodes of the other two electrodes.

Claim 20

A floatless fluid level gauge comprising: three electrodes immersed in the fluid to be gauged, said electrodes being so configured that the ratio of the volume of said fluid between a first and third of said electrodes with respect to the volume of said fluid between said third and a second of said electrodes has a generally unique value for each depth of immersion of said electrodes in said fluid; means for maintaining a potential difference between two of said electrodes, whereby an electric current is caused to flow between said two electrodes, the other of said electrodes being disposed in the current path between said two electrodes; and, means for sensing the potential of said third electrode, wherein said first and second electrodes comprise two right cylindrical segments of unequal cross-section disposed coaxially one within the other, and said third electrode is a right cylindrical segment of cross-section intermediate to the cross-sections of the electrodes of the other two electrodes.

Claim 21

The gauge of claim 15 including additionally a non-conductive coating applied to one surface of one of said other two electrodes whereby the effective conductive area of said coated electrode is caused to vary as a non-linear function of the level to which fluid contacts said coated electrode.

Claim 22

The gauge of claim 16 wherein said coated electrode is the outermost of said cylindrical segments and said coated surface is the inner surface thereof, and the innermost of said cylindrical segments is maintained at said reference potential and includes additionally a filtering screen at the lower end thereof whereby said innermost cylindrical segment is adapted to be used for filling a container with the fluid to be gauged.

Claim 23

The gauge of claim 15 including additionally a mounting plate and a plastic spacer block attached thereto for supporting said electrodes in the fluid to be gauged.

Claim 24

The gauge of claim 18 wherein said means for sensing potential comprises: utilization means responsive to said potential at said third electrode; and, means connecting said third electrode to said utilization means.

Claim 25

The gauge of claim 19 wherein said means for connecting comprises an integrated circuit device disposed within said plastic spacer block.