Field measurement and analysis of CO2 concentration in underground railway tunnels

To test the air quality in underground railway tunnels of two typical systems—close mode operation and platform screen doors, conducts two field measurements by detecting the CO2 concentration. Studies the distribution and the variation of the CO2 concentration in details. The research result shows that the CO2 concentration of the tunnel is determined by the CO2 concentration of the station in close mode operation, while it is very close to the outdoor CO2 concentration in platform screen door system.