A sensor for measuring electrochemical corrosion potential, and a method for manufacturing a sensor, the sensor comprising a tubular ceramic probe having a closed tip at one end, the probe at least partially filled with a powder comprising metal and metal oxide; a metal support tube having one end receiving an opposite end of the probe, and joined thereto by a braze joint therewith; an electrical conductor extending through the support tube and into the probe, and having an end buried in the powder for electrical contact therewith; and a protective band bridging the probe and tube at the joint for sealing thereof, the protective band consisting essentially of a metallic coating.