| 摘要 |
PURPOSE:To recover light transmittivity easily and securely at low cost and to make a recovery from damage by heating an image guide when the image guide is damaged by radiation and decreases in light transmittivity. CONSTITUTION:A heater wire 2 is wound around an outer circumference of a bundle of many optical fibers 1 made of quartz glass to form a heating means, and a sheath 3 for the heat insulation and protection of the optical fibers 1 is provided around them. If the optical fiber 1 decreases in light transmittivity owing to radiation damage and provides a darker picture, the heater wire 2 is energized to heat the optical fiber 1, whose light transmittivity is recovered. This method is used preferably when optical fibers are used for monitoring, specially, nuclear power facilities, etc. Further, a heating device may be provided as a different body instead of winding the heating wire around the optical fibers directly. |
