抄録
The auther reported in the before number (No. 8, Vol. 21) that the sulphur in the cast iron can be determind by measuring density of its sulphur print, and introduced the new type mean densitometer for this purpose. In this number he reported the practical result of this method at the foundry during one year. This result shows that the new method is serviceable. This method can not be applied for much content of sulphur, because the reflecting density of photographic paper does not increase lineally, according as increase of sulphur. The density of print is nearly saturated from 0.3% to 0.5% of sulphur. The influence to varies the density of print is studied, and the condition of printing is decided. The density of print is little affected by the other elements in the commercial cast iron, for instance P, Ni, Cr, Al, Mn and Cu. When (C+Si)<5%, the density is a little more increase than soft common cast iron.
In this case, K=0.196. When Magnesium is added to molten cast iron for nodular graphite, this method is not serviceable as common cast iron, especially high content of sulphur.
