GB 223.50-1985 Methods for chemical analysis of iron,steel and alloy--The phenylfluorone-CTMAB direct photometric method for the determination of tin content (English Version)
1994GB/T 223.50-1994 Methods for chemical analysis of iron, steel and alloy. The phenylfluorone-CTMAB direct photometric method for the determination of tin content
1985GB 223.50-1985 Methods for chemical analysis of iron,steel and alloy--The phenylfluorone-CTMAB direct photometric method for the determination of tin content
GB 223.50-1985 Methods for chemical analysis of iron,steel and alloy--The phenylfluorone-CTMAB direct photometric method for the determination of tin content was changed to GB/T 223.50-1994 Methods for chemical analysis of iron, steel and alloy. The phenylfluorone-CTMAB direct photometric method for the determination of tin content.