Abstract: To make a jacketed thermoelement, two metal wires, one of which is pure platinum, preferably of at least 99.9, and even higher purity, and the other being a platinum/rhodium alloy are included in a ceramic element. The wires are first threaded into capillary openings of a cylindrical ceramic element which is jacketed by a jacket of platinum-rhodium alloy or INCONEL (TM). The initial assembly is hammered, thereby crashing the ceramic, and drawn to reduce the outer diameter of the metal jacket tube to fit the inner diameter of an auxiliary tube, for example of a copper-tin alloy which is fitted over the metal jacket tube. The thus formed composite is then passed through a sequence of drawing dies, preferably in a single drawing pull, in which each die reduces the cross-section by about 9-10%, until the desired outer diameter of the metal jacket tube (4) is reached; this diameter may be in the order of 0.3 mm, after starting with an outer diameter of just under 5 mm.