Validation and Verification Techniques for EMC for Functional Safety

Safety systems must maintain low risks over their lifetimes. Where electromagnetic interference (EMI) could affect risks, an adequate level of electromagnetic (EM) performance is required. This is known as 'electromagnetic compatibility (EMC) for Functional Safety'. In most areas of safety system engineering, EM immunity testing is relied upon as the sole method of proving that EMI will not cause excessive safety risks. But a paper presented at the 1st IET International Conference on System Safety, and several other papers presented since 2004, have shown that it is not practicable (or affordable) to prove that systems are safe enough by relying solely on EM immunity testing. In all other technical areas, including software, the achievement of sufficiently low safety risks requires the use of proven good design techniques, plus a range of validation and verification techniques, including (but not limited to) appropriate tests. This generally accepted safety-engineering approach is not (yet) applied to EMC for Functional Safety. A previous paper has described proven good design techniques for EMC for Functional Safety. This paper briefly describes a range of validation, verification and appropriate EM immunity testing techniques for the achievement of EMC for Functional Safety. Many of these techniques can also be used to help control environmental risks, and can help reduce financial, security or legal risks in high-reliability, mission-critical, critical national infrastructure or legal metrology systems.