IEC TS 60079-42:2019 provides guidance for equipment manufacturers where electrical safety devices are used to reduce the likelihood of potential ignition sources becoming effective in Ex Equipment located in Explosive Atmospheres. Electrical safety devices perform a safety function to control potential ignition sources from both, electrical or non-electrical Ex Equipment in explosive atmospheres.
This Technical Specification may also be applied to a combination of elements performing a safety function. For example: Sensor, Logic system, Final element. This Technical Specification can also be used for assessing the safety device independently, without being designed for a specific Ex Equipment.
This Technical Specification does not apply to:
mechanical control equipment such as pressure relief valves, mechanical governors and other mechanical safety devices
the use of gas detection
control equipment to prevent the occurrence of explosive atmospheres, e.g. inerting systems and ventilation systems
mitigation of an explosion