Method and apparatus for measuring the temperature of a molten metal

Measured and apparatus for measuring the temperature of a molten metal Abstract The invention is related to a method for measuring the temperature of a melt, particularly of a molten metal, with an optical fiber, whereby the optical fiber (10) is fed into the melt through a disposable guiding tube (40) and whereby the optical fiber (10) and an immersion end (50) of the disposable guiding tube (40) are immersed into the melt both having a feeding speed whereby both feeding speeds are independent from each other. Further it is related to a device and an apparatus for measuring the temperature of a melt, particularly of a molten metal, comprising an optical fiber (10) and a disposable guiding tube (40), having an immersion end (50) and a second end, opposite to the immersion end (50), whereby the optical fiber (10) is partially arranged in the disposable guiding tube (40), whereby the inner diameter of the disposable guiding tube (40) is bigger than the outer diameter of the optical fiber (10), whereby an elastic plug (30) is arranged at the second end of or within the disposable guiding tube (40), whereby the optical fiber (10) is fed through the elastic plug (30) and whereby the elastic plug (30) reduces a gap between the optical fiber (10) and the disposable guiding tube (40). The apparatus comprises a fiber coil and a feeding mechanism for feeding the optical fiber (10) and the disposable guiding tube (40), whereby the feeding mechanism comprises at least two independent feeding motors, one for feeding the optical fiber (10) and one for feeding the disposable guiding tube (40). Fig. 3b