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ANSI/IES LM-80-20
Approved Method: Measuring Luminous Flux and Color Maintenance of LED Packages, Arrays, and Modules
LEDs typically exhibit very long operational life characteristics and, depending on drive current and use conditions, can be in use for 50,000 hours or longer.The light output from LEDs slowly decreases over time. This characteristic of declining output without sudden and permanent failure creates a risk that an LED-based lighting product near end of life may be operating but performing outside the product’s specification, or outside required codes, standard practices, or regulations. LEDs may also undergo gradual shifts in the emitted spectrum over time that may result in unacceptable appearance or color rendering, or degraded efficacy. This Approved Method describes the procedures by which LEDs are tested for luminous (or radiant, or photon) flux maintenance, and chromaticity maintenance or wavelength changes over time when operated under controlled environmental and operational conditions. The resulting measurements may be used for comparison of LEDs, and they may be utilized in models that project long-term changes in light output during the life of the LEDs.
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Illuminating Engineering Society of North America [iesna]
