Preparation of Trace HF Gas Reference Material for Fault Diagnosis of SF6 Electrical Equipment

Accurate detection of HF gas content is of great significance for fault diagnosis of SF
₆
electrical equipment. In order to ensure the accuracy and reliability of the analysis results in practical application, it is necessary to prepare traceable HF gas certified reference materials (CRMs) as the guarantee. To avoid the liquefaction of HF gas caused by excess addition, a small volume, high-pressure gas cylinder is applied to indirectly transfer the parent gas to the target gas cylinder in this paper. After two dilutions, 49.82 μmol/mol and 100.4 μmol/mol HF gas CRM in the background gas of N
₂
is successfully developed by gravimetric method. The results show that the standard uncertainty of the weighing process of HF gas certified reference material is less than 0.1%. Compared with the traditional gravimetric method, the transfer technique of small amount of gas improves the accuracy of weighing, reduces the dilution step, and solves the problem of preparing gas with low saturated vapor pressure, which can increase the reliability of SF
₆
decomposition products detection.