IMPROVEMENT OF MELTING APPARATUS FOR THE VACUUM FUSION OXYGEN ANALYSIS BY THE CARBON CYLINDRICAL FURNACE.

Instead of the usual induction or carbon spiral furnace, the carbon cylindrical furnace was used as the melting furnace in a vacuum-fusion oxygen analysis. This furnace had some strong points as compared with the other furnace; that is, easy manufacture of heating units, easy operation, high and easily controllable operating temperature and some other points. By this furnace the blank test, analyisis of standard sample, the research of operating temperature and the comparison between the Herty method and the vacuum-fusion method. The mean CO value of blank test of this furnace were 0.066cc/15min. at 1900°C and 0.029cc/15min. at 1700°C and this value were seemed to be superior than the blank value of usual carbon spiral furnace. The extrusion of Al-killed samples at 1700°C was imperfect and the extrusion at about 1900°C was required. The results of six standard samples were coincident within the value 0.0071±0.0003%.