Abstract The gravimetric preparation process of trace impurities reference materials in high purity helium including hydrogen, neon, oxygen, argon, nitrogen, methane, monoxide carbon and dioxide carbon are introduced. The process includes technology of gravimetric method,quantity of relative impurity in dilution gas,stability test and etc. The amount-of-substance fraction range of eight kinds of trace impurities is between 0.5μmol/mol and 4.0μmol/mol and the expand uncertainty is between 1%~3%(k=2) according to national standard GB/T 4844—2011. The accuracy of value is verified by the international key comparison organized by CCQM. Comparing with current two-class reference materials, developed reference materials in the kinds and uncertainty keep ahead in domestic.
2018, Vol. 39 
