| 摘要 |
PURPOSE:To make the quality of resin after curing uniform by a method wherein the concentration of inert gas in resin curing atmosphere is detected on the relationship between the concentration of the inert gas and that of oxygen gas so as to control the concentration of the inert gas in said atmosphere on the basis of the detected value of the concentration of oxygen. CONSTITUTION:During the passing of an optical fiber 19 through a transparent tube 11, an uncured resin coated layer 21 is cured by the ultraviolet energy emitted from a ultraviolet light radiator 10. A gas sensor 7 measures the concentration of the oxygen in the discharge gas sent from the transparent tube 11 so as to input the measured value in a control appliance 9 in order to electrically or electronic process and the concentration of the inert gas in the transparent tube 11 is detected from the relationship between the concentration of the inert gas and that of oxygen. When the concentration of the inert gas is below the predetermined value or, in other words, the concentration of the oxygen in the transparent tube 11 exceeds the predetermined value, the opening of a flow control valve 5 is made larger so as to make the supply of the inert gas from a gas feeding system 7 to the transparent tube 11 larger. When said concentration is equal to the predetermined value, the control appliance 9 keeps the opening of the flow control valve 5 as it is. |
