What is Lumen Depreciation ?
Lumen Depreciation simply compares the amount of light produced from a light source or from a luminaire when it is brand new to the amount of light output at a specific time in the future. For instance, if a luminaire produced 1000 lumens of light when it was brand new and now produces 980 lumens of light after 3,000 hours, then it would have Lumen Depreciation of 2% at 3,000 hours. Sometimes this is stated as Lumen Maintenance, which in our example would be 98% Lumen Maintenance from the original light output.
The appropriate Lumen Depreciation target is usually based on the application and the requirements set forth by customers. Since the human eye generally can’t detect a change in light output so Zhejiang Tianlong Optoelectronics Technology Co., Ltd's R&D team had made a inspection on the Lumen Depreciation.
And the report has confirmed when used 600-1,000hours the LED is most efficient, lumen can be higher than the original lumen. After 1,800Hours the Lumen Depreciation happens. 2,000hours -1.1%, 3,000hours -1.6%, 4,000hours -2.2%, 5,000hours around -3%, 6,000hours -4.6%. Now the testing is continuing, will updating later.
Please see details data as following:
Since the human eye generally can’t detect a change in light output until there has been 30% depreciation, so after 1 year or 2year, some even several months, if you can notice the depreciation, it means you have bought bad LEDs or fake LEDs!!
Now in the LED field many customers can not distinguish between good and bad, always cheat by Illegal manufacturer, because firstly they looks the same. Practice is the criterion for testing truth, so please choose the reliable manufacturer.
29th June, 2012
Zhejiang Tianlong Optoelectronics Technology Co., Ltd