Research on Method for Reproducing Halogen Leak Rate Based on Reference Materials

Reference leaks used for calibration of halogen leak detectors have consistently presented high uncertainty issues. To reduce the uncertainty of halogen leak rate values, this study proposes a method for reproducing leak rates based on gas reference materials. Through formula derivation, the conversion relationship between gas concentration and leak rate under specific conditions was established and experimentally verified. Results demonstrated excellent consistency between the reproduced leak rate and the standard leak rate when measured by halogen leak detectors (with normalized deviations of 0.41 and 0.21 in two experiments). The uncertainty sources of the reproduced leak rate were analyzed, including contributions from the gas reference material, intake flow rate, temperature, pressure, molar mass, and gas constant. After calculation and synthesis of these components, the relative expanded uncertainty of the leak rate reproduction based on gas reference material was determined to be 2.5% (k=2). This value is significantly lower than that of common reference leaks, and the method demonstrates good operability.