| 摘要 |
<p>PURPOSE:To enable a continuous temperature measurement to be accurately performed until almost the whole temperature measuring nozzle is melted down, by changing the position of the light receiving end of an optical fiber bundle toward the outside of the container of the temperature measuring nozzle in accordance with a meltdown quantity from the inside of the container. CONSTITUTION:A plurality of optical fibers 5 are arranged with light receiving ends shifted in the direction of buried depths. When a temperature measuring nozzle 10 is used, a purge gas G2 is blown in between guide pipes 16 and the fibers 5. The gas is discharged from nozzle ports 15, 15... with the cooling of the fibers 5 to prevent a molten steel from invading the fibers 5 and the nozzle ports 15 from being closed. In this condition, the radiated light from the molten steel is caught by the fibers 5 to be transmitted to a changeover device 17. In the changeover device 17, a fiber 5 in measuring positions coming incapable of measurement with the loss of the nozzle 10 is change to be connected to subsequent shallow and sound fiber 5. Therefore, received light energy corresponding to only the fiber thus used is inputted to a thermometer.</p> |
