Please Note: The current Round Robin experiment will close on 2024-06-30.

Calibration scales of the current WMO/IAEA Round Robin Experiment.

A World Meteorological Organization (WMO) Central Calibration Laboratory (CCL) is responsible for maintaining and distributing the WMO Mole Fraction scale for a specified gas in air. NOAA Earth System Research Laboratory (ESRL) Global Monitoring Division (GMD) is the WMO CCL for CO₂, CH₄, N₂O, SF₆, and CO. Max Planck Institute for Biogeochemistry (MPI-BGC) laboratory in Jena, Germany is the CCL for H₂ and for the stable isotopes of CO² (δ¹³C and δ¹⁸O).

The following table summarizes the calibration scales used to assign values to the current WMO Round Robin cylinders. Please Note: For these experiments, H₂ values have been assigned to the WMO Round Robin cylinders by NOAA, the stable isotopes of CO₂ values have been assigned by the University of Colorado (CU), Institute of Arctic and Alpine Research (INSTAAR), Stable Isotope Laboratory (SIL), and O₂/N₂ values have been assigned by the National Center for Atmospheric Research (NCAR).