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Relationship between Lumen Degradation and Ambient Temperature of LED Luminaires.

Accel over 5 years ago

Hello Everyone,

I would like to ask how would someone calculate the lumen degradation of a certain LED Luminaire in varying ambient temperatures.

For example, this luminaire from TRILUX -------->https://www.trilux.com/products/en/7650B-LED4000-840-ET-05/

It has a mean rated service life L85 (50 deg C) = 50 000 hrs

How would I calculate in order to get the L value at e.g. t = 25 deg C?

TRILUX has their own Lifetime Calculator and it gave an L value of 94.

How did they arrive with that value? Does it have a formula or only a rule of thumb?

Thanks,

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0 gkenyon over 5 years ago

It is likely to be based on standard statistical calculations for MTTF, modified by an acceleration factor A_f using the Arhenius Equation:

I've not plugged numbers in to check, mind ... you'd need to know, or search up, the activation energy of the type of LED junction you were considering to do this. Basically, this is the forward voltage drop of an individual LED at the point the LED turns on.
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0 gkenyon over 5 years ago

It is likely to be based on standard statistical calculations for MTTF, modified by an acceleration factor A_f using the Arhenius Equation:

I've not plugged numbers in to check, mind ... you'd need to know, or search up, the activation energy of the type of LED junction you were considering to do this. Basically, this is the forward voltage drop of an individual LED at the point the LED turns on.
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