Abstract: A temperature sensor is supported in a device which floats in a liquid, the temperature of which is to be determined. Typically the sensor is the hot thermocouple element of a thermocouple and the liquid is a molten metal; the device may be constructed to float with the temperature sensor disposed at a desired distance below the upper surface of the liquid.

Abstract: An elongated protective device for an immersion pyrometer. The device comprises a self-supporting inner sheath made of a ceramic material having virtually no open pores and a protective, crack-free outer ceramic casing at least partially surrounding the inner sheath. The inner ceramic sheath has an interior cavity extending from an open end of the sheath internally to a closed end for receiving a thermocouple element. The thermocouple element is then positioned within the cavity with the hot junction of the thermocouple element contacting the closed end of the ceramic sheath. The device provides good corrosion, shock and oxidation resistance for pyrometers when immersed into molten metals and by-products at high temperatures.