2020GOST 31610.15-2020 Explosive atmospheres. Part 15. Equipment protection by type of protection ?n?
2014GOST 31610.15-2014 Explosive atmospheres. Part 15. Equipment protection by type of protection «n»
2012GOST 31610.15-2012 Electrical apparatus for explosive gas atmospheres. Part 15. Construction, test and marking of type of protection ?n? electrical apparatus