To permit a comparison of the power inputs of ballasts and lamp circuits for fluorescent lamps,
CENELEC (Comité Européen de Normalisation Electrotechnique), the European committee for
electronic standardisation, has developed a standard for the measurement of the total input powerof ballasts-lamp circuits. The umbrella organisation of European luminaire and ballast manufacturerassociations (CELMA) has introduced a classification of the total input power of ballast-lamp circuits(EEI = Energy Efficiency Index). According to this, the input power is divided into seven classes perlamp type. The following table details the EEI classes, whereby A1 (dimmable), A2 and A3 are forelectronic, B1 and B2 for low-loss and C and D for conventional electromagnetic ballasts.