Abstract: An improved particle sensing transducer apparatus and method for studying the physical properties of particles suspended in an electrolyte solution. The transducer apparatus includes a first chamber, at least a portion of which contains a quantity of the electrolyte solution with a first electrode disposed therein. A second chamber is provided, at least a portion of which contains a quantity of the electrolyte solution with a second electrode disposed therein. The transducer further includes an orifice for establishing a constricted electrical path by providing a passageway for a sample flow of electrolyte solution containing the particles between the two chambers. The improvement comprises a fluid retarding, ion conducting material, such as a gel, frit or membrane, interposed between the sample flow and at least one of the electrodes so as to pass an ionic current while retarding the electrolyte flow from the electrode.

Abstract: A sensor and method are disclosed for measuring electrokinetic effects across a double layer formed at the boundary between a solid wall and an ionic liquid flowing through a channel. In one embodiment, a passive electrode is located in a cavity forming a tee section with the channel through an orifice of approximately the same size as the channel. A passive second electrode in electrical communication with one side of the double layer is placed on the other side of a porous plug which is located in a second cavity directly opposite the orifice and which is flush with the channel walls. The double layer being investigated is formed on the flush portion of the porous plug. Thus both electrodes are out of the flowing liquid. An electrokinetic potential, labeled the K-effect potential, was measured by the two electrodes.

Abstract: A measuring apparatus for measuring the charging degree of a liquid is provided with a casing accommodating an insulating material in the middle of a circulating system in which a base liquid is circulated.The charging degree of a test liquid is measured by the change of a charging quantity when the test liquid is injected by a syringe in the circulating system while a charging quantity which occurs from friction between the insulating material in the casing and the flowing base liquid is detected.