In order to resolve the traceability issue in micro-gas flow instrument

a micro-gas flow traceability method based on the principle of active constant temperature and pressure

and zero balancing dynamic verification is proposed. The standard facility of flow verification is developed based on the method. Double-piston drived mechanical structure

software and hardware of verification system

based on Lab VIEW platform and PLC are designed. Uncertainty evaluation on the devices is conducted as well. Experimental results show that the standard flow facility can maintain stability of flow and state parameter during verification

the uncertainty of verification is prior to 0. 3 %

which can meet the requirements of verification or calibration for micro-gas flow instrument.