The IES method for measuring lumen and color maintenance of LED packages, arrays and modules held at set case temperatures, commonly 55 and 85 degrees C plus a third chosen by the maker, for at least 6,000 hours. The data feed the TM-21 extrapolation method, which projects L70 and similar life figures but caps reported values at six times the test duration. It applies to the LEDs, not the driver or the luminaire.
LM-80 data only goes to 85 C case temperature, and our fixture runs the boards at 95, so the L70 claim doesn't apply.
Also heard as
- LM-80 data
Do not mix it up with
- LM-79: LM-79 measures complete luminaire performance at one moment; LM-80 tracks LED package depreciation over time.
Related terms
L70
The number of operating hours until an LED product's light output falls to 70 percent of its initial value.
Junction temperature
The temperature of the active semiconductor region inside an LED, which governs its output, color and lifetime.
LM-79
The standard method for measuring a complete LED luminaire's light output, power, efficacy, color and distribution.
LED
Light-Emitting Diode: a semiconductor light source, made white for lighting by coating a blue chip with phosphor.