Abstract: The present invention relates to an improved cathode element for the production of electrolytic copper, and more particularly to an improved cathode element of the reusable type which includes a cathode plate. With the intention of preventing a sleeve-like copper build-up around the cathode plate, the cathode element is provided with electrically insulating edge strips along at least those side edges of the cathode element which, in an active position, are located in the electrolyte bath, wherein the electrically insulating edge strips are chemically bonded to the cathode plate, preferably by vulcanization or by gluing.

Abstract: An electrode (10) intended for measurement of relative permittivity. Each one of the electrically conductive electrode elements of the electrode (12) of an even number, e.g. n, there being electrodes includes a corresponding line wire (20 and 22, respectively) for connection to a measuring bridge or the like. The electrode elements (12) are mutually separated by means of spacer means (18) of electrically insulating material. The lead-in wires (20,22) of adjacent electrode elements (12) can be connected in pairs for measurement. The electrode elements (12) are arranged on an electrode body (14) shape like to a rod and of an electrically insulating material. The electrode elements (12) are tubular and are arranged in recesses (16) with adapted measures in the electrode body. The spacer means (18) comprise of annular members intergral with the electrode body (14).