| 摘要 |
<p>A light guide (1) is made of a transparent refractory corrosion resistant material, for example, leuco-sapphire, and has two parts: a narrow one (2) shaped as a rod, and a wide one (3) provided with a flat butt-end (3a) forming the working butt-end of the light guide (1). The wide part (3) of the light guide (1) serves, in relation to the narrow part (2), as an optical chamber which forms the radiation of the working butt-end (3a) as essentially the radiation of a totally black body. The ratio between the cross-section area of the narrow part (2) at the point of its conjunction with the wide part (3) and the area of the lateral surface (3b) of the wide part (3) does not exceed 0.5. A method provides for incorporation of the light guide (1) into the lining (6) so that the wide part (3) faces the melt (5), the narrow part (2) faces the pyrometer (7) and the geometrical axis of the light guide (1) passes through a point of the internal surface of the lining (6) situated in a zone (1) of maximum circulation of the melt (5). Said point is located at a height (h) in relation to the lowest level (5a) of the melt (5), that height being not less than the sum of the thickness (t) of the lining (6) at that level and the half of the largest diameter (d) of the wide part (3) of the light guide (1). The temperature of the melt (5) is then determined by measuring characteristics of the thermal radiation emitted by the melt (5) in a zone directly adjoining the abovementioned point on the internal surface of the lining (6) and transmitted to that pyrometer through the light guide (1). </p> |
