Converter with a container for receiving molten metal and a measuring device for optically determining the temperature of the molten metal

The invention relates to a converter comprising a container for accommodating molten metal and a measuring device for optically determining the temperature of the molten metal with - an optical waveguide for guiding light emitted from the metal electromagnetic radiation to an optical detector, - an optical detector for determining the temperature of the metal from an analysis of the electromagnetic radiation, - arranged between the optical detector and the container through which fluid flows line in which the optical waveguide is guided at least in sections, and in which the optical fiber is transported by means of the fluid, wherein said optical detector is spaced from the container in an area in which the ambient temperature is less than 150 ° C.