Caro

How is LED lifetime evaluated — and what do L and B values mean?

In professional lighting design, LED lifetime is a critical quality parameter. It defines long-term visual consistency, reduced maintenance, project reliability, and operational efficiency. LEDs do not fail suddenly. Instead, their light output decreases slowly over time. For this reason, lifetime values are always defined using two parameters: L and B. The L value (Lumen Maintenance) defines how much of the original light output is maintained after a specified number of operating hours. The B value (Statistical Performance) indicates the percentage of luminaires that may drop below this lumen level, due to production tolerances, ageing, or environmental conditions. For example, a lifetime of 50.000 hours L80B20 means that after 50.000 hours:

80% of the initial luminous flux is maintained
And up to 20% of the luminaires may deliver less than 80% of the initial output

This B value does not represent total luminaire failure, but a statistical prediction of reduced light output in a certain percentage of products. At Karizma Luce, we test all LEDs used in the Caro track spotlight according to the LM-80 standard — a globally recognised method for measuring lumen maintenance over time. To project the final lifetime value, the TM-21 calculation method is applied. This is the IES-recommended method for predicting lumen depreciation based on real LM-80 data. Our lifetime specifications are always published in the product sheet for each version. For the Caro track spotlight, the typical value is 50,000 hours L80B20, providing reliable, consistent performance for professional retail, hospitality, or gallery environments. Would you like to explore other versions of the same spotlight? Discover Caro SF (surface-mounted version) or Caro REC (recessed version) for different installation needs. Correct lifetime information reflects technical transparency, and it defines the long-term value and efficiency of your lighting project.


670AB92712F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670AB93012F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670AB94012F0	4000 K	Included ON/OFF	K	940 (4000K / CRI90)
670AW92712F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670AW93012F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670AW94012F0	4000 K	Included ON/OFF	K	940 (4000K / CRI90)
670CB92715F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670CB93015F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670CB94015F0	4000 K	Included ON/OFF	K	940 (4000K / CRI90)
670CW92715F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670CW93015F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670CW94015F0	4000 K	Included ON/OFF	K	940 (4000K / CRI90)
670DB92725F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670DB92735F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670DB92745F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670DB92760F0	2700 K	Included ON/OFF	K	927 (2700K / CRI90)
670DB93025F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670DB93035F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670DB93045F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)
670DB93060F0	3000 K	Included ON/OFF	K	930 (3000K / CRI90)