2. Use SIEMENS PLC and touch screen as human-machine dialogue interface;
3. Pneumatic pressurization to prevent refrigerant pollution, ensure stable pressure supply and reliable safety;
4. Mass flowmeter as a measuring device to ensure the accuracy of refrigerant perfusion;
5. The humanized design of the filling gun, the structure is small and exquisite, light weight, easy for workers to operate, low failure rate and convenient maintenance;