Capacitive fluid level sensing apparatus

Claim 1

A FLUID LEVEL SENSING SYSTEM COMPRISING, IN COMBINATION: A SOURCE OF VOLTAGE HAVING FIRST AND SECOND END TERMINALS AND AN INTERMEDIATE TERMINAL CONNECTED TO A POINT OF REFERENCE POTENTIAL; AN AMPLIFIER HAVING AN INPUT AND AN OUTPUT; MEANS CONNECTING THE OUTPUT OF SAID AMPLIFIER TO ENERGIZE SAID VOLTAGE SOURCE; A FIRST CAPACITOR CONNECTED BETWEEN THE FIRST TERMINAL OF SAID VOLTAGE SOURCE AND THE INPUT OF SAID AMPLIFIER; A LEVEL SENSING CAPACITOR ADAPTED TO BE MOUNTED IN A CONTAINER OF FLUID AT A PREDETERMINED LEVEL, SAID SENSING CAPACITOR COMPRISING A SUPPORT ROD CONNECTED TO THE POINT OF REFERENCE POTENTIAL, A FIRST CAPACITOR PLATE CONNECTED TO THE SECOND END TERMINAL OF SAID VOLTAGE SOURCE, FIRST INSULATIVE MEANS MOUNTING SAID FIRST CAPACITOR PLATE TO SAID ROD, A SECOND CAPACITOR PLATE CONNECTED TO THE INPUT OF SAID AMPLIFIER, SECOND INSULATIVE MEANS MOUNTING SAID SECOND CAPACITOR PLATE ON SAID ROD, AND CONDUCTIVE MEANS MOUNTED ON SAID ROD INTERMEDIATE AND EXTENDING BEYOND SAID FIRST AND SECOND INSULATIVE MEANS SO THAT ANY CONTAMINANTS BUILDING UP ALONG SAID INSULATIVE MEANS BETWEEN SAID FIRST AND SECOND CAPACITOR PLATES MUST CROSS SAID CONDUCTIVE MEANS.