System for sensing

Claim 1

IN COMBINATION, A SENSING PROBE, A SUPPORT PLATE, THE SUPPORT PLATE BEING CONNECTED TO GROUND, A TRANSFORMER HAVING A FIRST WINDING AND A SECOND WINDING, THE FIRST WINDING OF THE TRANSFORMER HAVING ONE TERMINAL CONNECTED TO GROUND AND ANOTHER TERMINAL CONNECTED TO THE PROBE, AN ADJUSTABLE CAPACITOR CONNECTED ACROSS THE FIRST WINDING OF THE TRANSFORMER, A FIRST TRANISTOR, A SECOND TRANSISTOR, A SOURCE OF CONSTANT FREQUENCY ENERGY, MEANS PROVIDING A SUBSTANTIALLY CONSTANT CURRENT BETWEEN THE SOURCE OF ENERGY AND THE FIRST TRANSISTOR, SAID MEANS INCLUDING THE SECOND WINDING OF THE TRANSFORMER SO THAT THE VALUE OF CURRENT FLOW THROUGH SAID MEANS IS ADJUSTED BY THE VALUE OF THE CAPACITANCE ACROSS THE FIRST WINDING OF THE TRANSFORMER, THE VALUE OF THE CAPACITANCE ACROSS THE FIRST WINDING BEING DEPENDENT UPON THE VALUE OF THE CAPACITANCE OF ADJUSTABLE CAPACITOR AND THE VALUE OF THE CAPACITANCE BETWEEN THE SENSING PROBE AND THE SUPPORT PLATE, CONNECTOR MEANS CONNECTING THE OUTPUT OF THE FIRST TRANSISTOR TO THE SECOND TRANSISTOR, SAID CONNECTOR MEANS INCLUDING PULSE TRANSMISSION MEANS, AND OUTPUT MEANS CONNECTED TO THE SECOND TRANSISTOR.