Résumé
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.
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.