Considerations for Hazard of Electromagnetic Radiation to Fuels (HERF)
This article outlines a holistic approach to determine what needs to be considered when evaluating a HERF risk. The paper will consider all aspects constituting a HERF risk and provide mitigation strategies to reduce the risk. RF induced arcs can ignite exposed fuel vapours. Potential hazards are commonly found on military platforms, including ships, aircraft and tactical vehicles. CENELEC, CLC/TR 50427: "Assessment of Inadvertent Ignition of Flammable Atmospheres by Radio Frequency Radiation" [1], guidance which identifies the following 4 conditions for a hazardous condition to exist: 1) An RF field of sufficient strength/energy needs to be presented. 2) A structure must be present capable of behaving as a receiving antenna. 3) A mechanism in the structure capable of delivering the received RF energy as a spark/arc must be presented. 4) The mechanisms in point above must be within a flammable atmosphere. A HERF assessment needs to determine whether all four conditions coexist to verify the existence of the hazard.