– the intergovernmental organization through which Member States act together
     on matters related to measurement science and measurement standards.
Search facility:

| Site map | News | Contact us
CCPR Working Group on Key Comparisons (WG-KC)

Terms of reference

CCPR Working Group on Key Comparisons (WG-KC)

The terms of reference of the WG-KC are to:

    establish and maintain a list of key and other comparisons in the field of photometry and radiometry, which will adequately support CMC claims by NMIs in this field of measurement in the spirit of the global MRA between NMIs;

    coordinate and schedule key comparisons, to review progress in comparisons and to recommend to the CCPR the inclusion of the results of key comparisons in Appendix B of the MRA database;

    provide supplementary guidelines and/or interpretations to the guidelines on conducting key comparisons included in the MRA, specifically for the field of photometry and radiometry;

    recommend general principles for the calculation of key comparison reference values in photometry and radiometry;

    provide advice to the WG-CMC on the range of CMCs supported by particular key comparisons;

    monitor and approve RMO key comparisons and provide advice on RMO supplementary comparison activities.


  • Dr Yoshihiro Ohno  (NIST)


  • KRISS (Korea Research Institute of Standards and Science)
  • LNE (Laboratoire National de Métrologie et d'Essais)
  • MIKES (VTT Technical Research Centre of Finland Ltd, Centre for Metrology / Mittatekniikan keskus)
  • NIM (National Institute of Metrology)
  • NIST (National Institute of Standards and Technology, United States Department of Commerce)
  • NMIA (National Measurement Institute, Australia)
  • NMIJ/AIST (National Metrology Institute of Japan, AIST)
  • NPL (National Physical Laboratory)
  • NRC (National Research Council of Canada)
  • PTB (Physikalisch-Technische Bundesanstalt)
  • VNIIOFI (All-Russian Scientific Research Institute for Optical and Physical Measurements, Rosstandart)
  • Also, pilots of ongoing key comparisons
  • All other official CCPR members and observers, RMO Technical Committee chairs in the field of photometry and radiometry or their representatives, as well as any additional ad hoc observers approved by the WG-KC chair, may attend WG-KC meetings as observers.

Guidelines for membership:


Task Groups of the CCPR Working Group on Key Comparisons (WG-KC)
  • TG1
  • Pilot comparison for spectral regular transmittance in the UV Natasha Nel-Sakharova (NMISA)
  • TG2
  • RMO linkage Emma Woolliams (NPL)
  • TG3
  • Comparison analysis Annette Koo (MSL)
  • TG4
  • Pilot study for the use of alternative standards for photometric comparisons Erkki Ikonen (MIKES)

  CCPR: Upcoming meetings
2–3 July 2018: Meeting of the CCPR WG-CMC (2 July, afternoon / 3 July, morning)
3 July 2018: Meeting of the CCPR WG-SP (3 July, afternoon)
4 July 2018: Meeting of the CCPR WG-KC

CCPR summary
General information
Members of the CCPR
CCPR working groups
KC and SC registration form
CCPR workshops
List of planned RMO comparisons in PR
CCPR publications and bibliography
Photographs of the CCPR
Key comparisons
Open documents
CCPR documents
CCPR-WG-SP documents