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.
Yoshihiro Ohno, Steven W. Brown, Thomas C. Larason
Abstract
Under the framework of Mutual Recognition Arrangement (MRA) for national measurements standards and for calibration and measurement certificates issued by National Metrology Institutes (NMIs) signed in 1999, an international comparison of spectral responsivity in the near infrared region 900 nm to 1600 nm, designated CCPR K2.a, was conducted under Consultative Committee of Photometry and Radiometry (CCPR). This comparison was piloted by National Institute of Standards and Technology and participated by 15 laboratories. The comparison was conducted following the Guidelines for CIPM key comparisons (1999) and the data was analyzed following the Guidelines for CCPR comparison report preparation (2006). The results of most of the laboratories agreed within ±1 % difference in the entire spectral range except for a few outliers having the largest deviations up to 4 % from the Key Comparison Reference Values at some wavelengths. The unilateral and bilateral degrees of equivalence of all participating NMIs are provided.
Ohno, Y.
, Brown, S.
and Larason, T.
(2009),
Report on the Key Comparison CCPR K2.a-2003, BIPM Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=904379, https://doi.org/10.1088/0026-1394/47/1A/02002
(Accessed October 8, 2025)