Grey water interface valve liquid level sensor system

Abstract

Embodiments of the present disclosure generally provide a grey water interface valve liquid level sensor system. The liquid level sensor system may deliver information about the water level and the water movement that occurs in a water reservoir. A control unit may then activate a valve to open so that the water can be removed via vacuum.

1 . A water level sensing system, comprising:
 at least one differential sensor and at least one absolute sensor;   wherein the water level sensing system is positioned on an outer surface of a liquid reservoir such that the system does not contact liquid in the reservoir, and   wherein the sensors function at an excitation frequency of greater than about 4 MHz.   
     
     
         2 . The system of  claim 1 , wherein the water level sensing system comprises a set of at least three sensor plates arranged such that a first plate receives a sine signal, a second plate receives an inverted signal, and a third plate serves as a read plate. 
     
     
         3 . The system of  claim 2 , wherein the third plate is positioned between the first and second plates. 
     
     
         4 . The system of  claim 2 , wherein the at least three sensor plates are switchable between providing absolute and differential readings. 
     
     
         5 . The system of  claim 2 , wherein the at least three sensor plates are switchable between functioning as sine signal receiver, inverted signal receiver, or read plate. 
     
     
         6 . The system of  claim 1 , wherein the at least one differential measuring sensor and the at least one absolute measuring sensor comprise capacitive sensors. 
     
     
         7 . The system of  claim 1 , wherein the sensors function at an excitation frequency of between about 4 MHz and about 20 MHz. 
     
     
         8 . The system of  claim 1 , wherein the sensors function at a plurality of frequencies and are designed to frequency hop when needed. 
     
     
         9 . The system of  claim 1 , wherein the water level sensing position is installed on a grey water reservoir on an aircraft. 
     
     
         10 . A grey water interface valve sensor system for use on a passenger vehicle, comprising:
 a wash basin, a reservoir, a control unit, a valve, a vehicle vacuum system, and a level sensing unit, the level sensing unit comprising at least one differential sensor and at least one absolute sensor positioned on an outer upper portion of the reservoir; and at least one differential sensor and at least one absolute sensor positioned on an outer lower portion of the reservoir, wherein the level sensing system directs the control unit to activate the valve in order to allow the vacuum system to drain the reservoir.   
     
     
         11 . The system of  claim 10 , wherein the level sensing unit comprises a series of level sensing plates positioned along a substantial portion of an outer portion of the reservoir. 
     
     
         12 . The system of  claim 10 , wherein the level sensing unit directs the control unit to open the valve if the reservoir is almost full and to close the valve before the reservoir is fully drained. 
     
     
         13 . The system of  claim 10 , wherein the water level sensing system comprises a set of at least three sensor plates arranged such that a first plate receives a sine signal, a second plate receives an inverted signal, and a third plate serves as a read plate. 
     
     
         14 . The system of  claim 13 , wherein the third plate is positioned between the first and second plates. 
     
     
         15 . The system of  claim 13 , wherein the at least three sensor plates are switchable between providing absolute and differential readings. 
     
     
         16 . The system of  claim 13 , wherein the at least three sensor plates are switchable between functioning as sine signal receiver, inverted signal receiver, or read plate. 
     
     
         17 . The system of  claim 10 , wherein the at least one differential measuring sensor and the at least one absolute measuring sensor comprise capacitive sensors. 
     
     
         18 . The system of  claim 10 , wherein the sensors function at an excitation frequency of between about 4 MHz and about 20 MHz. 
     
     
         19 . The system of  claim 10 , wherein the sensors function at a plurality of frequencies and are designed to frequency hop when needed. 
     
     
         20 . (canceled)