INRiM contributions in the characterization and certification of reference materials

► INRiM as NMI carries out activities on reference materials in the chemical field. ► Realisation of aqueous solutions and gas mixtures with primary methods are presented. ► The contribution to the certification of RMs by INAA is analysed. ► Main features of the produced RMs and of the used procedures are given. ► Measurement uncertainties for the different cases are evaluated.