Invesigation on dispersions between CISPR25 chambers for radiated emissions below 100 MHz

CISPR25 [1] is the reference standard for EMI characterization of automotive equipments. This standard specifies major requirements regarding the semi anechoic chamber characteristics, such as its size, the ground plane minimum size, the ground connection to the Faraday cage quality, the absorbers´ minimum performances... Nevertheless the degrees of freedom afforded in this standard for these particular parameters are identified as key factors leading to significant deviations in results obtained on emissions measurement performed on equipments between “CISPR25 compliant chambers”. This paper highlights these effects and try to provide some analysis and proposals in order to get a better management of testing results between labs.