| 摘要 |
PURPOSE:To hold the roundness of a core and also to ensure high accuracy for the measurement between cores, by arraying plural core materials with a prescribed space and providing the quartz glass fine powder to the outside of each core material. CONSTITUTION:Both ends of core materials 10 and 10a are fixed to a pair of fixing tools 11a and 11b so as to secure a prescribed space between the materials. Then an oxyhydrogen flame burner 12 is ignited. The burner 12 is set at the obliquely lower part of the material 10. Thus the quartz glass fine powder 12' is grown and then sprayed to the outside of the materials 10 and 10a to form a porous material 14 at the outside of these materials. Thereafter, the materials 10 and 10a are turned centering around the material 10a positioned at the center and at the same time raised up. After the growth of the material 14 is through over the entire length, the tools 11a and 11b are removed. Then the material 14 is sintered and turned transparent in a high-temperature oven, and this temperature is set lower than the softening point of the materials 10 and 10a respectively. In such way, the roundness is ensured for the materials 10 and 10a. |
