IEC 62431 pdf – Reflectivity of electromagnetic wave absorbers in millimetre wave frequency – Measurement methods This International Standard specifies the measurement methods for the reflectivity ofelectromagnetic wave absorbers (EMA) for the normal incident, oblique incident and eachpolarized wave in the millimetre-wave range. In addition，these methods are also equallyeffective for the reflectivity measurement of other materials: measurement frequency range: 30...