DIN EN 61341:2012-08

While the light output of lamps is normally characterized by the luminous flux, for reflector lamps it is characterized by the centre beam intensity together with the beam angle(s). This European Standard gives guidance with regard to the measurement and interpretation of these two basic characteristics of reflector lamps in order to allow the comparability of reported values. The adopted principles may help to classify lamps into beam angle groups; they are not intended for the assessment of individual lamps.