Links

SIM - Inter-American Metrology System
http://www.sim-metrologia.org.br

Nist - National Institute of Standards and Technology
http://nist.gov

PTB - Physikalisch-Technische Bundesanstalt
http://www.ptb.de

CIE - International Commission on Illumination
http://www.cie.co.at

BIPM - Bureau International des Poids et Mesures
http://www.bipm.fr

OIML - International Organization of Legal Metrology http://www.oiml.org