Measurement of uncertainty in Electrical Fast Transient test

Electrical Fast Transients (EFT) are commonly generated by relay chattering, interruption of inductive load, etc. IEC 61000-4-4 standard describes about the immunity requirements, test method / procedures and specifications for conducting the EFT test. The EFT test is applicable for almost all electrical / electronic products for `CE marking´. The quantification of measurement uncertainty for any EMC test including EFT test is a main concern nowadays. Standards like CISPR 16-4 explain about measurement uncertainty for Conducted Emission & Radiated Emission tests. They do not cover the conducted immunity tests. Publications like LAB 34 specify briefly about measurement uncertainty of conducted transient immunity measurement. An effort has been made in this paper to calculate and present the measurement uncertainty of EFT test on the basis of LAB 34 guidelines.