摘要 |
A slit is disposed as diaphragm in the beam path of a mass spectrometer. The slit width is to be variable in the simplest possible manner. Manual, electric motor-driven, thermoelectric or piezoelectric adjustment devices are known. According to the invention a pneumatic adjustment is provided. A Bourdon tube (12) moves a lever (14), at one end (18) of which slits (19, 20, 21) of differing slit widths are disposed. The lever movements are limited by abutments (22, 23).
|