Conductivity cell and measuring system

Abstract

A four electrode T-shaped conductivity cell has one pair of external elecdes affixed to opposite sides of the stem member and one pair of internal electrodes affixed to diametrically opposite arcuated portions of the inner wall surface of an open-ended tube which serves as the crosshead member of the T. The "voltage" electrodes of the cells are connected in the input circuit of a high gain amplifier which has a negative feedback loop in which the "current" electrodes are connected. An AC reference signal is coupled to this input circuit and is canceled by the voltage developed across the "voltage" electrodes. The feedback current, which is responsible for this condition and is proportional to the conductivity of the electrolyte, is converted to an output voltage whose magnitude with respect to that of the reference signal yields a ratio which is linearly proportional to the conductivity.

Dependencies are inferred from the claim text.