Kapazitive Meßvorrichtung

摘要

A capacitive measuring device a measuring capacitor with a measuring electrode 3 arranged from a counter-electrode 8, and there being dielectric material for analysis arranged between the electrodes or continuously being conveyed between them, a time varying measuring current IC being supplied to the measuring electrode and the capacitor voltage UC being measured and evaluated, there being arranged to the side of a measurement zone provided between the electrodes which may be a flow channel or duct 1 for the material to be analysed, at least one side wall delimiting the measurement zone, and the measuring electrode being surrounded by a plurality of guard ring and/or auxiliary electrodes 61-6N spaced apart therefrom in a staggered arrangement and at least partly covering the side walls and each of which is constantly being corrected via a potential-controlling circuit 17 to the potential of the measuring electrode so as to thereby largely compensate for leakage currents to the said electrodes, the side wall in the region of the measurement zone being virtually completely covered with auxiliary electrodes, arranged in a ribbon shape parallel to the measuring electrode or in a two-dimensional grid, and each of the auxiliary electrodes being wired to its potential-controlling circuit in a manner that minimises any flow of current into the auxiliary electrodes. <IMAGE>