The rated output of a luminaire corresponds to the luminaire’s active power P if it is operated with its rated voltage (e.g. 230 V) in an environment featuring its rated ambient temperature (e.g. 25°C) at maximum luminous flux ΦB (rated luminous flux, see also chapter "Luminous efficacy") in a thermal equilibrium. For unification purposes, this value is used to balance the energy consumption of a luminaire. It contains the power consumption of all luminaire components necessary for operation. Dimming levels are currently not considered, i.e. active power measurements are performed at 100% lumen output. If temporal luminous flux degradation in a luminaire is compensated via constant light output, the data sheet usually contains the power consumption for the luminaire’s initial state. In addition, active power achieved at the end of the rated service life must be specified. It is closely connected to the degradation, which must be considered regarding rated service life (see chapter "Rated service life with constant light output").