NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
A large-chip standard LED with superior long-term stability have been developed at NIST. The standard LED uses a large, specialty die rated for 50 W but is operated under 3 W to eliminate aging effect. The standard LED was seasoned for one year and measured for its long-term stability for three years. The measurement result shows that the long-term stability is on the level of 0.1 % in the three-year time. The LED can be used as a transfer standard for luminous intensity, luminance, and total luminous flux.
Proceedings Title
Proceeding of the 29th Quadrennial Session of the CIE
Zong, Y.
, Zhao, W.
and Miller, C.
(2021),
STANDARD LEDS WITH SUPERIOR LONG-TERM STABILITY, Proceeding of the 29th Quadrennial Session of the CIE, Washington, DC, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928008
(Accessed October 10, 2025)