IEC 60027-1A*CEI 60027-1A (1976), IDT * ISO 31-1 (1978-03), MOD * ISO/DIS 31-1 (1990-02), MOD * ISO 31-2 (1978-03), MOD * ISO/DIS 31-2 (1990-02), MOD * ISO 31-2 AMD 1 (1998-12), MOD * ISO 31-3 (1978-03), MOD * ISO/DIS 31-3 (1990-03), MOD * ISO 31-4 (1978-03), MOD * ISO 31-5 (1979-02), MOD * ISO/DIS 31-5 (1990-05), MOD * ISO 31-6 (1980-12), MOD * ISO 31-7 (1978-03), MOD * ISO/DIS 31-7 (1990-05), MOD * ISO 31-8 (1980-12), MOD * ISO/DIS 31-8 (1990-06), MOD * ISO 31-9 (1980-12), MOD * ISO/DIS 31-9 (1990-06), MOD * ISO 31-10 (1980-12), MOD * ISO/DIS 31-10 (1990-07), MOD * ISO/DIS 31-12 (1990-07), MOD * ISO 31-13 AMD 1 (1985-08), MOD * TS 294 ISO 31-1 (2005-02-24), NEQ * TS 295 ISO 31-2 (2005-02-24), NEQ * TS 296 ISO 31-3 (2005-02-24), NEQ * TS 297 ISO 31-4 (2005-02-24), NEQ * TS 1308 ISO 31-5 (2005-02-24), NEQ * TS 1309 ISO 31-7 (2005-02-24), NEQ * TS 1507 ISO 31-9 (2005-02-24), NEQ * TS 1827 ISO 31-10 (2005-02-24), NEQ * TS 2908 ISO 31-13 (2005-02-24), NEQ