| 摘要 |
PROBLEM TO BE SOLVED: To provide a method, etc., for manufacturing a glass substrate, capable of suppressing contamination of foreign matters in a molten glass in the step of refining the molten glass.SOLUTION: A method for manufacturing a glass substrate comprises: a melting step of heating a glass raw materials to form a molten glass; a refining step of refining the molten glass; and a molding step of molding a glass substrate from the molten glass. In the refining step, the molten glass flows through the inside of the refining pipe made of platinum or platinum alloy so as to form a vapor phase space being a space above the surface of the molten glass. The refining pipe has a vent pipe projected outward from the outer wall surface of the refining pipe and for passing a gas including platinum existing in the vapor phase space. The vent pipe includes a measuring pipe provided for capturing and measuring the gas; and an oxygen analyser connected with the measuring pipe and for measuring the oxygen concentration of the gas. In the measuring pipe, the longitudinal cross section of an opening end on the side of capturing the gas is inclined against the longitudinal direction of the measuring pipe.SELECTED DRAWING: Figure 4 |
