1. APPARATUS FOR DETECTING THE PROXIMITY OF AN ELECTROSTATICALLY CHARGED BODY COMPRISING: A PLURALITY OF DETECTOR ELECTRODES POSITIONED IN SPACED RELATIONSHIP WITH A COMMON DETECTOR ELECTRODE AND ADAPTED TO RECEIVE ELECTROSTATIC CHARGES FROM THE ELECTROSTATICALLY CHARGED BODY, SAID CHARGE BEING INVERSELY PROPORTIONAL IN MAGNITUDE TO THE DISTANCE BETWEEN SAID CHARGED BODY AND EACH OF SAID ELECTRODES, SAID ELECTRIC CIRCUIT MEANS COUPLED TO SAID DETECTOR ELECTRODES AND TO SAID COMMON DETECTOR ELECTRODE FOR SENSING THE CHARGE POTENTIALS DEVELOPED BETWEEN SAID COMMON DETECTOR ELECTRODE AND EACH OF SAID DETECTOR ELECTRODES AND FOR DIVIDING ONE OF SAID CHARGE POTENTIALS BY THE OTHER OF SAID POTENTIALS TO DEVELOP AN OUTPUT SIGNAL RELATED TO THE DISTANCE BETWEEN SAID DETECTOR ELECTRODES AND SAID ELECTROSTATICALLY CHARGED BODY.