the light emitting diode is reduced. It will therefore lose some of its luminosity over the period of use. The definition of LED lifetime assumes a reduction in luminous intensity to 70% of the original luminous intensity. This period is specified in hours as the LED service life. Realistic values are around 40,000 to 50,000 hours. If the LED is operated for 8 hours a day, this would mean that it has a service life of about 13 years, after which it still radiates with a luminous intensity of 70% of the original luminous intensity.
The LED service life is influenced by various factors.
On the one hand, their chemical and physical components age depending on the current, ambient temperature and cooling, environmental influences such as humidity, mechanical stresses and chemical influences. As the forward current increases, the internal temperature rises, which results in a decrease in luminous fl ux and a reduction in brightness. This influence can be compensated by improved cooling.