Capacitive measuring device
First Claim
1. In a capacitive measuring device for dielectric material to be analyzed, the device includinga measuring electrode (3) a distance from a counter-electrode (8) with the material disposed therebetween,current means for supplying to the measuring electrode a time-variable measuring current (IC), andmeasuring means for measuring and evaluating a capacitance-dependent capacitor voltage (UC);
- the improvement comprising;
a plurality of auxiliary electrodes (6N, 6NA) disposed between the measuring electrode (3) and the counter-electrode (8) on two sides of the material, the auxiliary electrodes being disposed in a staggered formation;
each of the auxiliary electrodes being coupled to a respective potential-controlling circuit (17) including minimal-current-flow means for compensating for leakage currents into or out of each of the auxiliary electrodes.
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Accused Products
Abstract
A capacitive measuring device with a measuring electrode (3) arranged some distance from a counter-electrode (8), a dielectric material for analysis is arranged between the electrodes (3, 8), and a measuring current (IC) is supplied to the measuring electrode (3) and the capacitance-dependent capacitor voltage (UC) is measured and evaluated. The measuring electrode (3) is surrounded by a plurality of guard ring and/or auxiliary electrodes (13, 6N, 6NA) spaced apart therefrom in a staggered arrangement and at least partly covering the side walls (18), and each of which is constantly being corrected via a potential-controlling circuit (17) to the potential of the measuring electrode (3), so as to thereby largely eliminates leakage currents to the guard electrodes (13, 6N, 6NA), in the region of the measurement zone the side wall (18) being virtually completely covered with additional guard electrodes (61-6N; 61A-6NA), divided in a ribbon shape parallel to the measuring electrode (3) or divided in a two-dimensional grid, and each of the guard electrodes is wired to its potential-controlling circuit (17) in a manner that minimizes any flow of current into the guard electrodes (61-6N; 61A-6NA).
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Citations
22 Claims
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1. In a capacitive measuring device for dielectric material to be analyzed, the device including
a measuring electrode (3) a distance from a counter-electrode (8) with the material disposed therebetween, current means for supplying to the measuring electrode a time-variable measuring current (IC), and measuring means for measuring and evaluating a capacitance-dependent capacitor voltage (UC); the improvement comprising; a plurality of auxiliary electrodes (6N, 6NA) disposed between the measuring electrode (3) and the counter-electrode (8) on two sides of the material, the auxiliary electrodes being disposed in a staggered formation; each of the auxiliary electrodes being coupled to a respective potential-controlling circuit (17) including minimal-current-flow means for compensating for leakage currents into or out of each of the auxiliary electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
Specification