Ensuring metrological traceability of volume units and gas flow rate to the National Measurement Standard Base of Ukraine

The processes of globalization in the world economy demand the elimination of technical barriers in international trade, particularly in the energy sector. To resolve conflicts between gas suppliers and consumers, the implementation of the concept of metrological traceability of measuring instruments to the base units of the SI system through a continuous calibration chain becomes relevant. Simultaneously, it is necessary to apply the concept of measurement uncertainty to assess the accuracy of measurements. An important aspect of measurements is measurement traceability insurance, as one of the most effective ways to determine the measurement uncertainty is to assess the accuracy of the instrument. This concept plays a key role in the processes of calibration, conformity assessment, and verification of measuring instruments, and it is also essential for participation in international trade. Metrological traceability ensures the reliability of measurement results through the establishment of a continuous calibration chain. The paper focuses on improving the methods, development of relevant devices, and on the creation of a regulatory framework that would ensure the linkage of working measuring instruments used for natural gas accounting with national primary state measurement standards. A traceability chain has been established for measurements from the national primary measurement standard of the unit of volume and volumetric gas flow rate to working measuring instruments, with normalized uncertainty values throughout the entire hierarchy of gas flow rate unit transfer. To ensure measurement traceability, regulatory documents, which establish calibration procedures, have been implemented in Ukraine's metrological practice. Theoretical and experimental studies of meters have been conducted to use them as transfer measurement standards. Particular attention has been paid to the stability and reproducibility of results, as well as the adaptation of methods to international measurement standards.