IEC/TR 61341:2010描述了测量和指定反射器灯的中心光束强度和相关联的光束角度的方法。它适用于: -白炽灯， -卤化钨， -用于一般照明目的的气体放电灯和基于LED的反射灯。不适用于投影灯等特殊用途的灯具。第二版取消并取代了1994年出版的第一版，构成了技术修订。由于越来越多地使用配备反射器的LED灯，范围已经扩大，测量条件也包括在内，以便考虑到这些灯。此外，为了更容易理解不同轴和不同强度之间的关系，添加了两个图。如果中心光束强度非常低，则应报告发光强度分布而不是中心光束强度（“蝴蝶”分布）。

IEC/TR 61341:2010 describes the method of measuring and specifying the centre beam intensity and the associated beam angle(s) of reflector lamps. It applies to:
- incandescent,
- tungsten halogen,
- gas-discharge and LED based reflector lamps for general lighting purposes. It does not apply to lamps for special purposes such as projection lamps. This second edition cancels and replaces the first edition published in 1994 and constitutes a technical revision. Due to the increasing use of reflector equipped LED lamps, the scope has been broadened and measurement conditions been included in order to take account of these lamps. Further, for easier understanding of the relation between the different axis and different intensities, two figures have been added. The luminous intensity distribution shall be reported instead of the centre beam intensity, if the latter is very low ("butterfly" distributions).