This part of IEC 60079 gives the specific requirements for the construction, testing and marking of electrical apparatus, parts of electrical apparatus and Ex components with the type of protection encapsulation “m”.This part of IEC 60079 only applies for encapsulated electrical apparatus, encapsulated parts of electrical apparatus and encapsulated Ex components (hereinafter always referred to as “m” apparatus) where the rated voltage does not exceed 10 kV with a relative tolerance of +10 %.This standard supplements the general requirements in IEC 60079-0.