Lumen maintenance is the luminous flux output remaining (expressed as a percentage of the initial output) at any selected elapsed operating time.
Lumen maintenance is the converse of lumen depreciation.
GB Requirements: the lumen maintenance is no less than 78% at 2000 hours.
Foreigh advanced level: lumen maintenance is no less than 90% at 2000 hours.
US Energy Star: lumen maintenance is no less than 80% at its 40% of rated life.
China current level: enterprises who focus on quality and adopt protective film technology could meet the national standard.
The induction lamps manufactured by Shanghai Lango Lighting Company adopt the latest production technology, and their lumen maintenance could reach 96% at 2000hours.