Liquid gaging system lost sensor recovery

Claim 2

In a liquid gaging system wherein a value related to a liquid quantity in a tank is determined by the system based on signals from a plurality of sensors, the accuracy of the value being dependent upon the validity of the signals from the sensors, an apparatus for reducing error in the value introduced by an incapacitated sensor, comprising: the plurality of sensors, each sensor providing a liquid measurement signal relating to a liquid depth at a particular location in the tank; means for selectively monitoring the liquid measurement signal of each individual sensor, the means for selectively monitoring being connected to the sensors; means for identifying at least one sister sensor corresponding to each sensor; and means for determining an estimated liquid depth corresponding to the incapacitated sensor by using the liquid measurement signal of the at least one sister sensor corresponding to the incapacitated sensor and for determining the value based on the liquid measurement signals and the estimated liquid depth, the means for determining being connected to the means for selectively monitoring and the means for identifying; whereby the value has less error associated with it than if an invalid liquid measurement signal from the incapacitated sensor were used to determine the value.

Claim 3

The apparatus of claim 1 wherein at least one of the sensors comprises a capacitive probe.

Claim 4

The apparatus of claim 2 wherein the capacitive probe has an essentially uniform capacitance per unit length.

Claim 5

In a liquid gaging system wherein a value related to a quantity of liquid in a tank is determined by the system based on signals from a plurality of probes, the accuracy of the value being dependent upon the validity of the signals from the probes, an apparatus for reducing error in the value introduced by an incapacitated probe, comprising: the plurality of probes for mounting in the tank, each probe having a length, each probe providing a wetted sensor length signal related to the portion of the probe immersed in the liquid, the portion of the probe so immersed being a wetted sensing length of the probe; means for selectively measuring the wetted sensor length signal of each individual probe, the means for selectively measuring being connected to the probes; means for identifying at least one sister probe corresponding to each probe; and means for determining an estimated wetted sensing length of the incapacitated probe by using the wetted sensor length signal of the at least one sister probe corresponding to the incapacitated probe and for determining the value based on the wetted sensor length signals and the estimated liquid depth, the means for determining being connected to the means for selectively measuring and the means for identifying; whereby the value has less error associated with it than if an invalid wetted sensor length signal from the incapacitated probe were used to determine the value.

Claim 6

In a liquid gaging system wherein a value related to a quantity of liquid in a tank is determined by the system based on signals from a plurality of probes, the accuracy of the value being dependent upon the validity of the signals from the probes, an apparatus for reducing error in the value introduced by an incapacitated probe, comprising: the plurality of probes for mounting in the tank, each probe having a length, each probe providing a wetted sensor length signal related to the portion of the probe immersed in the liquid, the portion of the probe so immersed being a wetted sensing length of the probe; means for selectively measuring the wetted sensor length signal of each individual probe, the means for selectively measuring being connected to the probes; means for identifying at least one sister probe corresponding to each probe; and means for determining an estimated wetted sensing length of the incapacitated probe by using the wetted sensor length signal of the at least one sister probe corresponding to the incapacitated probe and for determining the value based on the wetted sensor length signals and the estimated liquid depth, the means for determining being connected to the means for selectively measuring and the means for identifying; whereby the value has less error associated with it than if an invalid wetted sensor length signal from the incapacitated probe were used to determine the value.

Claim 7

The apparatus of claim 4 wherein: the apparatus further comprises means for storing the length of each probe, the means for storing being connected to the means for determining; and the means for determining comprises means for determining an estimated wetted sensing length of an incapacitated probe using the length of the incapacitated probe and the length of at least one sister probe.

Claim 8

The apparatus of claim 4 or 5 wherein at least one of the probes comprises a capacitive probe.

Claim 9

The apparatus of claim 6 wherein the capacitive probe has an essentially uniform capacitance per unit length.

Claim 10

In a liquid gaging system wherein a value related to a quantity of liquid in a tank is determined by the system based on signals from a plurality of probes, the accuracy of the value being dependent upon the validity of the signals from the probes, an apparatus for reducing error in the value introduced by an incapacitated probe, comprising: the plurality of probes for mounting in the tank, each probe having a length, each probe providing a wetted sensor length signal related to the portion of the probe immersed in the liquid, the portion so immersed being a wetted sensing length of the probe; means for selectively measuring the wetted sensor length signal of each individual probe, the means for selectively measuring being connected to the probes; means for identifying a first sister probe and a second sister probe corresponding to each probe; means for storing the length of each probe; means for determining an estimated wetted sensing length of the incapacitated probe using the length of the incapacitated probe and the length and wetted sensing length of the first sister probe and the second sister probe corresponding to the incapacitated probe and for determining the value based on the wetted sensor length signals and the estimated liquid depth, the means for determining being connected to the means for selectively measuring, the means for identifying, and the means for storing; whereby the value has less error associated with it than if an invalid wetted sensor length signal from the incapacitated probe were used to determine the value.

Claim 11

In a liquid gaging system wherein a value related to a quantity of liquid in a tank is determined by the system based on signals from a plurality of probes, the accuracy of the value being dependent upon the validity of the signals from the probes, an apparatus for reducing error in the value introduced by an incapacitated probe, comprising: the plurality of probes for mounting in the tank, each probe having a length, each probe providing a wetted sensor length signal related to the portion of the probe immersed in the liquid, the portion so immersed being a wetted sensing length of the probe; means for selectively measuring the wetted sensor length signal of each individual probe, the means for selectively measuring being connected to the probes; means for identifying a first sister probe and a second sister probe corresponding to each probe; means for storing the length of each probe; means for determining an estimated wetted sensing length of the incapacitated probe using the length of the incapacitated probe and the length and wetted sensing length of the first sister probe and the second sister probe corresponding to the incapacitated probe and for determining the value based on the wetted sensor length signals and the estimated liquid depth, the means for determining being connected to the means for selectively measuring, the means for identifying, and the means for storing; whereby the value has less error associated with it than if an invalid wetted sensor length signal from the incapacitated probe were used to determine the value.

Claim 12

The apparatus of claim 8 wherein at least one of the probes comprises a capacitive probe.

Claim 13

The apparatus of claim 9 wherein the capacitive probe has an essentially uniform capacitance per unit length.

Claim 14

The apparatus of claim 8 wherein the estimated wetted sensing length of the incapacitated probe (EST WSL PROBE ) is calculated using the formula EST WSL PROBE =LENGTH PROBE X (WSL S1 +WSL S2 )/(LENGTH S1 +LENGTH S2 ), LENGTH PROBE being the length of the the incapacitated probe, WSL S1 and WSL S2 being the wetted sensing lengths of the first and second sister probes respectively, and LENGTH S1 and LENGTH S2 being the lengths of the first and second sister probes respectively.