BS 05514-6-1992 (1999) ISO 3046-6-1990 ๐ BS 05514-6-1992 (1999) ISO 3046-6-1990 ๐ Scientific ๐ 1999
BS 06548-6-1995 (1999) IEC 706-6-1994 ๐ BS 06548-6-1995 (1999) IEC 706-6-1994 ๐ Scientific ๐ 1999