Fault Diagnosis
Mass Spectrometer Faults
Thermo Fisher Scientific
Prima PRO & Sentinel PRO Mass Spectrometers User Guide
9-5
The complete loss of mass peaks or a loss of resolution / peak shape
or sensitivity indicates the majority of faults. The following sections
are a list of possible causes of the above conditions.
Warning! High Voltages!
Voltages of up to 1 kV are present!
Exercise extreme caution at all times.
If there are no mass peaks, complete the following:
Check that the electronics are powered and that all leads are
connected and that all fuses are intact.
Check the Instrument Status light is green.
Check for satisfactory electron emission, filament current, source
current, trap current, and electron energy on the GasWorks Status
Window. If filament is short circuit the filament current will be at
filament limit with no trap current.
In Control Centre, set the Ion Energy and Focus Voltages to
zero
. Disconnect the socket from the source flange plug.
Check each pin on the source flange plug to all others and earth
(see
). Continuity should only be found between:
7 and 12 Filament 1
4 and 8 Filament 2
9 and 16 PRT
10 and 11 Source Heater
A plate in the source or collector assemblies may be disconnected
and / or charging up. This can only be confirmed by examining
the individual assemblies, which requires a full instrument
shutdown and removal of the assemblies from the vacuum
chamber.
Access the GasWorks Instrument Status window and check that
the magnet current is approximately 2.5 amps with mass 28
selected in Control Centre.
If the noise displayed on the computer screen does not increase
as the gain is increased, it is likely that the detector system is
inoperative.
Mass
Spectrometer
Faults
No Peaks
