What is lumen maintenance?
Lumen maintenance is an approach of measuring the light output (lumens) of a brand new light source and comparing that with its light output after a certain period of time. L70 and L50 are examples of lumen maintenance -- benchmarks for when 70 or 50 percent of a lamp or fixture's total light output remains.
Confused on what L70 means?
LEDs Magazine published a great article on this very subject:
"Rated lumen-maintenance life is measured in hours with associated percentage of light output, noted as Lp. In other words, L70 of 30,000 hours means that the tested LEDs produce 70% of the initial light output at 30,000 hours. If an LED has L50 of 30,000 hours, its lumen output decays faster than one with L70 of 30,000 hours."
For more information about lumen maintenance, contact Pacific Lamp.