| 摘要 |
PURPOSE:To permit detection of the convection state in a melt with ease of handling and high accuracy and responsiveness by providing a hollow pipe, gas supplying means and optical system, etc., to a titled device. CONSTITUTION:One end 11 of the hollow pipe 1 is an open end and one end 21 of an optical fiber 2 is connected to the other end 12. The gas supplying means 3 which supplies gas to the hollow part of the hollow pipe 1 and the optical system having a means 41 for projecting a laser toward the other end 22 of the fiber 2 and a laser detecting means 42 for detecting the reflected laser light ejected from the other end 22 of the fiber 2 are provided. At the time of detection, the hollow pipe 1 is inserted into a desired depth in the melt 5 and argon, nitrogen or the like is supplied to the pipe by using the means 3 to push the liquid level of the melt 5 down to one end 11 of the hollow pipe 1, then the melt is rested. If convection exists at this time, the liquid level at one end 11 of the hollow pipe 1 oscillations and, therefore, the reflected laser light changes. The presence of the convection is thus detected by the means 42. |
