The build of high speed gas flow calibration system based on dual buffer tanks and parallel standard meters

High speed gas flow calibration system chose air compressor as gas source, and the air outputted from the air source flows to three parallels of standard instruments after stabilized by the first-order buffer tank, and then after by the second, it flows to the three parallels of instruments for the calibration ultimately. By adjusting the pipelines of the electric valve opening propotion of three-way standard flowmeter area, the gas flowrate of the corresponding pipes will be changed; by choosing the pipelines of on-off state of different diameter in the area for the calibration, the flow calibration of the gas flowmeter of different diameter can be acquired. The system used Programmable Logic Controller (PLC)) as the main controller, electric control valve as a controlled object and closed-loop Proportion Integration (PI) or Proportion Integration Differentiation (PID) algorithm to adjust the valve opening so as to finish controlling the pipeline of gas flowrate, and by real-time display with configuration software MCGS, the quantitative system flow can be real-timely changed and then the system process control can be completed. By experimental verification, this system can be cognizant of the gas flow rate ranging from 3 m/s to 90m/s and the accuracy of flow control can be reached within 1%.