Abstract: Introduced the development of gas flow metering characteristics and needs, proposed the establishment of a various mediums micro gas flow calibration facility. Device indicators proposed by the actual needs demand. Analysis and comparison of characteristics and principles of commonly used gas flow standard, determining principle of PVTt. According to the design specifications and principle preliminary designed the proposal, and given analysis of the uncertainty.

Key words: Gas flow calibration facility, Micro flow, Various mediums, Uncertainty