The invention relates to a method for monitoring the state of vehicle chassis, particularly of rail vehicles, whereby physical quantities are measured on the chassis by means of sensors. Stabilization homogenizes the plasma energy density and concentration, leading to a more efficient reactor. When pulling up a touching element of the air suction-ventilation device, the air in the container space is drained out by the air suction-ventilation device to quickly remove the upper cover, to facilitate consumers for use, and to conveniently separate the air suction-ventilation device from the upper cover, for easily washing the upper cover with water. In the system, the bypass valve is provided at or close to the branching point in the exhaust pipe and a chamber is provided close to the branching point such that the conduit is connected to the bypass at the one end in the chamber.