The figure that reflects the drop in luminous flux of the light source (LLMF) takes into account failing LEDs, and deterioration of the light output over time. How do we determine this LLMF? We distinguish between the service life of LEDs at the component level and at the luminaire level.
At the component level we take into account the gradual deterioration of the luminous flux of the LEDs (parametric failure or B-lifetime), and the potential breakdown of LEDs (catastrophic failure or C-lifetime). At the luminaire level the complete failure of a luminaire is not relevant (see Luminaire Survival Factor). The LLMF corresponds with the B-lifetime at the luminaire level and hence takes on board the parametric as well as catastrophic failure of the individual LEDs in the luminaires.
In order to achieve an accurate, reliable LLMF for our luminaires, we carry out a ‘principal component analysis’:
- We determine the parametric failure at the component level in accordance with objective LM80/TM21.
- We are unable to calculate the catastrophic failure, but prefer to collaborate with manufacturers who make accurate data available. Whenever no measurement data are offered, we depend on electronic reliability models (MIL-HBK-217F)
Unified Glare Rating
Este é um modelo aproximado que expressa o risco de brilho.
Os valores padrão variam de UGR 16 (baixo risco de brilho) a UGR 28. Na norma EN12464 para iluminação de locais de trabalho, são impostos valores-limite para UGR para várias divisões.