Abstract: Arrangement and method for connecting a low-pressure connection of a gas analyzer with a test gas connection operated at a higher pressure level includes a connection line with a connection for the low-pressure connection and a connection for the test gas connection. A gas flow connection leads into the connection line, and a valve body is configured to be operable in the connection line for controlling a gas flow cross-section thereof for the connection to the low-pressure connection. The valve body is guided within a line section connected with the connection line on the gas flow connection, and the gas flow cross-section is formed between an interior wall thereof and the valve body.

Abstract: At an energy filter ions are deflected at the entrance side through a first electrostatic field between electrodes (3a', 3b'), traverse through a field-free volume (15) and enter through a shielding (11) into a further electrostatic deflection field between electrodes (7a', 3b'). The axes (A.sub.E, A.sub.A) of the beam entrance and exit are aligned and off-set with respect to the rotation axis (A'.sub.Z) of the cylinder forming the outermost electrode (7a').

Abstract: The mass spectrometer is of the type having a mass-spectrometric separation system located in an evacuable chamber, an inlet to the chamber for the gases to be examined, and an ion source and a detector for the gas mixture constituting auxiliary devices in the chamber and having walls. The gas inlet and the auxiliary devices are arranged in series, with the gas inlet being formed as an inlet nozzle operable to form a jet of the gas to be examined and so designed, relative to the auxiliary devices, as to direct the jet, as a molecular beam, through one auxiliary device without contacting a wall thereof so that the jet enters directly into the other auxiliary device. The ion source is arranged between the detector and the nozzle, and may be designed as a hot-cathode ion source. The detector may be designed as a hot-cathode ionization detector or as an ion source of a second mass-spectroscopic separation arrangement.