ID:
1438
Maker's Name:
Centronic
Where made:
England
Dimensions:
19.7 × 5 × 5 cm
This tube is the vacuum head of a quadrupole mass spectrometer system produced in the 1980s for residual gas analysis.
In principle it allowed the operator to determine whether the gas still in a vacuum system was air from a leak or water or something else outgassing from the walls.
The location of a leak might be detected by spraying a gas of known molecular mass around suspected areas.
A quadrupole mass spectrometer (as opposed to a magnetic deflection MS) uses static and oscillating electric fields between four parallel metal cylinders to deflect away ions of any but one desired charge-to-mass ratio travelling down the axis of the device to a detector. Scanning the field parameters allows a mass (to charge ratio) spectrum to be generated.
