Abstract

An electrolytic measurement system incorporating a probe for the measurement of the conductivity of fluids such as sewage and other industrial effluents. The probe has a smooth surface to passage of the fluid with flush-mounted electrodes arranged serially along the passage. The passage is formed within material that is an electrical insulator and is surrounded by a metallic shield symmetrically positioned with respect to the ends of the serially arranged electrodes. An electric potential is impressed between the outer electrodes and the shield, the latter being grounded, while an inner electrode is used for the measurement of electric current flowing through the fluid from the outer electrodes to the inner electrode. Sensing electrodes positioned between the inner and outer electrodes are utilized in a feedback circuit for sensing the electric field to vary the magnitude of the impressed voltage to maintain a constant magnitude of impressed field independently of the presence of electrochemical byproducts upon the electrode surfaces.