Project Description

LM-79 establishes testing methodology to create a level field for product evaluation. It looks at 25C ambient, power supply, stabilization, orientation, electrical instruments, and testing equipment. LM-79 defines what information is required; total light output, voltage, current, power, calculates efficacy, lumen distribution, CCT, CRI, spectral distribution, testing lab, and equipment used. LM-79 requires that solid state lighting products be tested to “Absolute Photometry.” Conventional HID/Fluorescent uses “Relative Photometry.” Absolute Photometry is lumen output of LED based luminaires and is dependent on the chip, thermal management, drive current, and optical system. LED based luminaires and lamps must be tested as a complete unit or system. Only DOE recognized CALiPER testing laboratories results should be utilized. LED luminaires and lamps do not “fail” like conventional sources This is known as L70 Total life is known as L70B50 LED luminaires and lamps gradually decrease in output over time IES has determined end of life of LED products to be when the lumen output is 70% of its initial (30% depreciation) This is known as L70 Total life is known as L70B50 L70B50 is the amount of time for the light output of 50% of a set of LEDs to fall to 70% of their original light output under a given set of operating conditions. The DOE has suggested that useful life of LEDs to be 35,000 to 50,000 hours. Claims beyond these values cannot currently be substantiated using available approved methods, or historical data to support claims beyond these levels. LM-80 however does not provide testing procedures for a complete luminaire only to measure the lumen maintenance of a LED package, array or module at 6,000 hours.