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In traditional lamp sources, lifetime is defined as the point at which 50% of the
lamps fail. This is also termed Mean Time Between Failure [MTBF]. LEDs are
semiconductor devices and have a much longer MTBF than conventional sources.
However, MTBF is not the only consideration in determining useful life. Everbright Lights uses the concept of useful light output for rating source lifetimes. Like traditional
sources, LED output degrades over time (lumen depreciation) and this is the
metric for SSL lifetime.
LED lumen depreciation is affected by numerous environmental conditions such as
ambient temperature, humidity, and ventilation. Lumen depreciation is also affected
by means of control, thermal management, current levels, and a host of other
electrical design considerations. Everbright Lights products are expertly engineered to
optimize LED life when used under normal operating conditions.
Lumen depreciation
information is based on LED manufacturers’ source life data as well as other third
party testing. Low temperatures and controlled effects have a beneficial effect on
lumen depreciation. Overall system lifetime could vary substantially based on usage
and the environment in which the system is installed.
Temperature and effects will affect lifetime. Everbright Lights rates product lifetime using
lumen depreciation to 50% of original light output. When the fixture is running at
room temperature using a color wash effect, the lifetime is in the range of 30,000-50,000 hours. This is based on LED manufacturers’ test data.
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