Jianzhong Jiao explains that the IES is publishing addendums to both the LM-80 standard for testing LEDs and documenting lumen maintenance, and to the TM-21 standard for projecting LED and SSL system life, improving and harmonizing the documents.
For continuous improvement in technology to be possible, it’s critical that corresponding testing standards are established and continue to be reviewed and improved. The solid-state lighting (SSL) industry is no exception. In 2008, IES published LM-80 for recommending how to test LED lumen maintenance. Three years later TM-21 was published as a recommendation for projecting long-term lumen maintenance of LEDs using the test data collected per LM-80. Based on the continuous improvement principle, IES is in the process of publishing an addendum to LM-80 and TM-21.