A method of measuring a temperature of a noble gas in a chamber includes providing the noble gas in the chamber. When opening the vacuum valve, a pressure medium line, which applies pressure to the opening cylinder space of the second piston-cylinder unit, is blocked during the first part of the opening process, and is released at the end of the first part of the opening process by the first control element. When a sensor detects that lateral acceleration or yaw rate exceeds a threshold value, an actuator drives pins to overcome the spring force, pushing the pins into the aperture.