lumen maintenance curve

life performance curve

For a source of light, a curve showing the variation of some characteristic of the source throughout its lifetime (e.g., lumens vs. life).
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.
References in periodicals archive ?
We can be heartened that there is now an industry standard for extrapolating LED lumen maintenance curves [IES 2011].