Abstract: An immersion probe as a preassembled unit includes a measuring head having a measuring element protected for minimizing trapping of gases by a sheath. The sheath is tapered toward a free end. The probe is adapted to be immersed in molten metal for measuring temperature and/or oxygen content.

Abstract: A temperature sensing device suitable for repeated immersions into a molten metal bath. The invention including a protective refractory sleeve which encases a portion of a generally cylindrical cardboard support tube. Within the suppprt tube is mounted a temperature sensing unit including a body portion, which is positioned within the end of the support tube, and a thermocouple extension portion, which includes a U-shaped quartz tube and which extends through and projects away from the end of the protection sleeve. The cardboard support tube is wrapped with a reflective foil substantially over its end and its entire peripheral surface. The U-shaped quartz tube is provided with an alumina coating to prevent degradation of the quartz material during repeated immersions into the molten metal bath. The combination increasing the number of useful immersions of the sensing unit prior to failure.

Abstract: A disposable thermocouple body is made from a lamination of flat paper plates. Sets of paper plates are of progressively increasing width up to the middle plate which supports a U-shaped thermocouple shield. The body is adapted to be mounted in one end of a lance for immersion into a molten metal bath.