Abstract: A measuring system includes a capacitance sensor adapted to be positioned in proximity to an object to be observed, signal generating circuitry cooperating with the sensor for producing an electrical signal output indicative of a characteristic of the observed object, and signal processing circuitry for processing the signal generated by the signal generating circuitry. The signal processing circuitry has a power supply and a grounding system separate from the power supply and grounding system of the signal generating circuitry, and a receiving element coupled to but physically spaced from a transmitting element of the signal generating circuitry. The signal generating circuitry thus responds only to the electrical output signal from the signal generating circuitry as transmitted by the transmitting element and is not affected by system perturbations on the ground system adjacent the sensor or in the power supply in the signal generating circuitry.