1990IEC 60079-3:1990 Electrical apparatus for explosive gas atmospheres; part 3: spark-test apparatus for intrinsically-safe circuits
IEC 60079-3:1990 Electrical apparatus for explosive gas atmospheres; part 3: spark-test apparatus for intrinsically-safe circuits was changed to IEC 60079-11:1999 Electrical apparatus for explosive gas atmospheres - Part 11: Intrinsic safety "i".