L-Prize; Bright Tomorrow Lighting Prizes

L Prize Winner Completes 50,000 Hours of Testing

September 30, 2016

High-temperature test bed Photo

The L Prize-winning lamp from Philips Lighting North America continues to show very stable light output, even
after 50,000 hours of continuous lumen-maintenance testing.

When the L Prize in the 60W replacement lamp category was awarded in August 2011, samples of the winning product had already survived more than 8,000 hours of accelerated long-term testing. A selection of 31 of those lamps passed the 50,000-hour point of continuous operation in August 2016. The average lumen maintenance for the 31 lamps after 50,182 hours was 93.0%, with no failures. At that rate it would take an average of 192,340 hours of operation for the lamps to reach 70% lumen maintenance (L70), if no other failure modes came into play before then. The average chromaticity change (Δu'v') of the 31 lamps after 50,182 hours of operation was 0.002 – a minuscule difference indicating that there was no detectable color shift, and that the light emitted today is indistinguishable from the light emitted five years ago.

These results show that well-designed LED integral lamps can operate very reliably over long periods of time, with excellent lumen and chromaticity maintenance.

Read the updated report on lumen maintenance testing of the Philips 60W L Prize entry.

Learn more about solid-state lighting at the U.S. Department of Energy Solid-State Lighting Web site

Last Updated: November 1, 2016
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