Abstract: A probe is provided for measuring the wear of a wall in a metallurgical vessel. The probe includes at least two electrically conducting elements which extend generally mutually parallel, and a tubular sheath wherein the electrically conducting elements extend interiorly of said sheath, and are mutually insulated via a refractory insulator. The probe is adapted to be implanted in the transverse direction in the wall of a metallurgical vessel with the distal end of each of the two electrically conducting elements being disposed at the interior surface of said wall. A measurement system is connected to the opposite proximal ends of the electrically conducting elements for measuring an electrical characteristic of the circuit formed by said elements that depends on the length of the elements. The probe has a diameter less than 1 mm achieved by stretching after the components have been assembled into an intermediate assembly having a larger cross sectional area than the final cross section.