This part of VDE 0170 specifies the construction and testing of intrinsically safe apparatus intended for use in an explosive atmosphere and for associated apparatus, which is intended for connection to intrinsically safe circuits which enter such atmospheres. This type of protection is applicable to electrical equipment in which the electrical circuits themselves are incapable of causing an explosion in the surrounding explosive atmospheres. This standard is also applicable to electrical equipment or parts of electrical equipment located outside the explosive atmosphere or protected by another type of protection listed in DIN EN 60079-0 (VDE 0170-1), where the intrinsic safety of the electrical circuits in the explosive atmosphere may depend upon the design and construction of such electrical equipment or parts of such electrical equipment. The electrical circuits exposed to the explosive atmosphere are evaluated for use in such an atmosphere by applying this standard. The requirements for intrinsically safe systems are provided in DIN EN 60079-25 (VDE 0170-10-1). This standard supplements and modifies the general requirements of DIN EN 60079-0 (VDE 0170-1), except as indicated in Table 1 of DIN EN 60079-25 (VDE 0170-10-1). Where a requirement of this standard conflicts with a requirement of DIN EN 60079-0 (VDE 0170-1), the requirements of this standard shall take precedence. If requirements in this standard are applicable to both intrinsically safe apparatus and associated apparatus the term "apparatus" is used throughout this standard. This standard is for electrical equipment only; therefore the term "equipment" used in this standard always means "electrical equipment". If associated apparatus is placed in the explosive atmosphere, it shall be protected by an appropriate type of protection listed in IEC 60079-0 (VDE 0170-1) , and then the requirements of that method of protection together with the relevant parts of DIN EN 60079-0 (VDE 0170-1). also apply to the associated apparatus. The responsible committee is K 241 "Schlagwetter- und explosionsgeschützte elektrische Betriebsmittel" ("Electrical apparatus for potentially explosive atmospheres") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.