Abstract: The mass value of gas is one of the most basic traceability parameters in gas flow measurement, and one of the common means to obtain the mass is to use the weighing method. The weighing of gas mass has its particularity compared with liquid in the principle of air buoyancy correction. In this paper, from the perspective of measurement principle and mechanical analysis of weighing equipment, as well as another perspective of the concept of conventional mass and vacuum mass in the field of mass measurement, the correction methods of direct weighing and substitution weighing are analyzed. Finally, a complete air buoyancy correction formula for gas mass weighing is given, and the buoyancy correction which is easy to be ignored in gas mass weighing is expounded.

Key words: Gas mass,  , Weighing,  , Air buoyancy correction