MEASURED-VALUE SENSOR FOR MAGNETIC-INDUCTIVE FLOWMETERS AND AN IMPROVED METHOD OF MAKING IT

A measured-value sensor for an inductive flowmeter comprises a fluid impermeable sintered ceramic measuring tube adapted to be positioned in a conductive-liquid flow path. Magnetic coils surround the tube and are adapted to apply a magnetic field to a conductive liquid traversing the path. A pair of diametrically opposite measuring electrodes contact the liquid traversing the path for tapping an induced voltage across the electrodes representing the flow of the liquid along the path, each of the electrodes having a metallic shaft traversing the tube substantially radially and sealingly sintered to the material of the tube. The ends of the ceramic measuring tube are provided with a flange, ground at its peripheral wall surface and fastened by shrinkage stress in a bore of a steel casing. After sintering of measuring tube, conductive paths are manufactured for the formation of grounding rings and other current-conducting components by applying a platinum paste on the ceramic measuring tube and reheating again subsequently. In the process, the paste compacts to form a thin conductor film which is firmly anchored on the surface of said measuring tube.