Sodium and potassium silicates for industrial use — Calculation of the ratio : silicon dioxide/sodium oxide or silicon dioxide/potassium oxide
工业用硅酸钠和硅酸钾——比率的计算:二氧化硅/氧化钠或二氧化硅/氧化钾
The document specifies the formula for the calculation. In this ratio, only sodium oxide and potassium oxide combined in the form of silicates is considered. Replaces ISO Recommendation R 1689-1970.