PRODUCTION OF GASEOUS CERTIFIED REFERENCE MATERIALS AT INRiM FOR AMOUNT OF SUBSTANCE FRACTION OF CO2

Due to the involvement of carbon dioxide (CO2) in the global warming effects, INRiM is developing certified reference materials (CRMs) of CO2 in synthetic air. The mixtures are prepared by gravimetry, a primary method, and verified by NonDispersive Infrared spectroscopy. The CO2 amount fraction in the mixtures and its associated uncertainty are the certified properties of the CRMs. A corresponding stability study of the amount fraction of CO2 is also ongoing. Further work foresees the development of CRMs for the isotopic composition of CO2 in air, after the participation in specific international comparisons.